{"title":"Extreme cold sleeping bag","description":"\u003ch2\u003eChoosing your winter sleeping bag based on real conditions\u003c\/h2\u003e\n\u003cp\u003eWhen \u003cb\u003ewinter camping\u003c\/b\u003e in France, nighttime temperatures vary between -5°C at low altitudes and -20°C above 3,000m in the Alps or Pyrenees. A \u003cstrong\u003ewinter sleeping bag\u003c\/strong\u003e should have a comfort rating at least 5°C lower than the expected minimums — to account for real-world variables such as fatigue, ambient humidity, and the quality of your insulated sleeping pad. A \u003cb\u003ewinter sleeping bag\u003c\/b\u003e rated for a comfort temperature of -10°C is suitable for nights down to -5°C in standard conditions; at altitude or in windy conditions, this margin becomes essential. The comfort temperature, the only reference value for sleeping without feeling cold, is distinct from the limit temperature — which corresponds to a standard man sleeping at the limit of comfort — and the extreme temperature, which is a theoretical safety threshold, not an operational metric.\u003c\/p\u003e\n\u003ch3\u003eCold-weather down bags: which insulation for extreme cold?\u003c\/h3\u003e\n\u003cp\u003eFor a \u003cb\u003ecold-weather down bag\u003c\/b\u003e with a comfort temperature below -10°C, 800 to 850 cuin natural down insulation offers the best weight-to-insulation ratio available. An \u003cb\u003eultra-light cold-weather down bag\u003c\/b\u003e with 850 cuin down and a comfort rating of -20°C weighs between 1,500 and 1,800 g — whereas an equivalent synthetic model exceeds 2.5 kg. Natural down loses its insulating properties if saturated with moisture: hydrophobic treatments reduce this risk in dry cold conditions, typical of high-altitude winter bivouacs. For trips in humid or prolonged conditions, synthetic insulation maintains minimal warmth even when wet. For further details on this choice, consult our \u003ca href=\"\/en\/blogs\/infos\/garnissage-sac-de-couchage-duvet-ou-synthetique-selon-lusage\"\u003eguide on down vs. synthetic insulation based on usage\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eUltra-light cold-weather sleeping bags: what the data says\u003c\/h2\u003e\n\u003cp\u003eFor mountaineering and winter climbing where every gram counts, an \u003cb\u003eultra-light cold-weather sleeping bag\u003c\/b\u003e with 800 to 850 cuin down and a comfort rating of -15°C weighs between 1,400 and 1,700 g depending on its construction. Below 1,400 g for this thermal level, the compromises in insulation thickness or shell fabric quality become significant. For an \u003cb\u003eextreme cold sleeping bag\u003c\/b\u003e used in expeditions or high-altitude mountaineering, look for a model with an adjustable anatomical hood, thermal shoulder collar, and a draft-protected zipper — these three elements reduce heat loss at the bag's critical points. The \u003ca href=\"\/en\/collections\/sac-de-couchage-moins-10\"\u003e-10°C sleeping bag\u003c\/a\u003e collection brings together models precisely calibrated for this threshold, suitable for winter outings that do not involve expedition conditions.\u003c\/p\u003e\n\u003ch3\u003eThe insulated sleeping pad: a deciding factor in winter bivouacking\u003c\/h3\u003e\n\u003cp\u003eThe sleeping pad accounts for 40 to 50% of the total insulation of your sleep system — the ground conducts cold much more efficiently than ambient air. For a \u003cb\u003ewinter down bag\u003c\/b\u003e used in bivouacs below -10°C, a pad with an R-value of 5 or higher is essential for the bag to perform to its full potential. A thermal liner provides an extra margin of +5 to +8°C, which is useful during the coldest nights or for those who get cold easily. Neglecting the sleeping pad in winter conditions is equivalent to underestimating the entire system, regardless of the quality of your \u003cb\u003ecold-weather sleeping bag\u003c\/b\u003e.\u003c\/p\u003e","products":[{"product_id":"sac-de-couchage-grand-froid-moins-30-aegismax-ultra","title":"Extreme cold -30°C mountaineering sleeping bag | Aegismax Ultra","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eUsage:\u003c\/b\u003e Mountaineering, winter expeditions, extreme cold\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eWeight:\u003c\/b\u003e 1,534 g (Regular) \/ 1,644 g (Long)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eComfort temperature:\u003c\/b\u003e -30°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eLimit temperature:\u003c\/b\u003e -38°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eFill:\u003c\/b\u003e 950 cuin white goose down, RDS certified\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eOuter fabric:\u003c\/b\u003e DWR water-repellent 10D IFlex® nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eThermal standards:\u003c\/b\u003e ISO 23537\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003eAbsolute insulation for high-altitude mountaineering\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAegismax Ultra\u003c\/strong\u003e is a thermal protection tool reserved for demanding expeditions. In temperatures as low as -30°C, \u003cb\u003emaintaining metabolic functions\u003c\/b\u003e during sleep is the top priority. This \u003cb\u003eexpedition sleeping bag\u003c\/b\u003e requires rigorous management of your bivouac environment (ground insulation and dry clothing) so that the exceptional quality of its fill can reach its full potential for heat retention.\u003c\/p\u003e\n\u003ch3\u003e3D architecture and maximum heat retention\u003c\/h3\u003e\n\u003cp\u003eThis model features \u003cb\u003ethree-dimensional sidewalls\u003c\/b\u003e and continuous wraparound baffles, a design that maximizes the expansion of the \u003cb\u003e950 cuin RDS-certified goose down\u003c\/b\u003e while eliminating dead compression zones. The adjustable thermal collar literally seals the interior. The use of an \u003cb\u003eultra-thin yet extremely durable 10D nylon\u003c\/b\u003e allows for optimal breathability, helping to limit moisture buildup before it freezes inside the fill.\u003c\/p\u003e\n\u003cp\u003eOn the opposite end of this extreme spectrum, if the winter season is over and you are looking for a minimalist down bag under 450 grams for purely summer nights (around 11°C), the ultra-compact \u003ca href=\"\/en\/products\/sac-de-couchage-10-degre-aegismax-air\" title=\"See the Aegismax Air summer bag\"\u003eAegismax Air\u003c\/a\u003e will radically lighten your carry.\u003c\/p\u003e","brand":"Ma boutique","offers":[{"title":"ULTRA \/ Long","offer_id":52581814763857,"sku":"14:175#Ultra-White-Lengthen;200007763:201336100","price":1139.0,"currency_code":"EUR","in_stock":true},{"title":"ULTRA \/ Regular","offer_id":52581814829393,"sku":"14:496#Ultra-White-Rgular;200007763:201336100","price":999.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/sac_de_couchage_grand_froid_aegismax_ultra.webp?v=1767131851"},{"product_id":"sac-de-couchage-moins-10-naturehike-sp1000","title":"Sleeping bag -10 degrees (-10.8°C) | Naturehike SP1000","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eWeight:\u003c\/b\u003e 1,650 g (M) \/ 1,720 g (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eComfort temperature:\u003c\/b\u003e -10.8°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eLimit temperature:\u003c\/b\u003e -18.6°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eThermal standard:\u003c\/b\u003e GB\/T 38426-2019\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eFilling:\u003c\/b\u003e 650 cuin duck down\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eOuter fabric:\u003c\/b\u003e Water-repellent 20D nylon\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003eThe thermal shield for long winter nights\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eNaturehike SP1000 extreme cold sleeping bag\u003c\/strong\u003e is designed for hikers facing environments where frost is a constant. Safety during winter bivouacking requires the ability to fully recover. This model relies on a robust structure and a generous amount of filling to stop heat loss in its tracks, creating a protective cocoon that is immediately noticeable as soon as you zip it up.\u003c\/p\u003e\n\u003ch3\u003eAirflow locking and ergonomic footbox\u003c\/h3\u003e\n\u003cp\u003eThe effectiveness of this \u003cb\u003ewinter sleeping bag\u003c\/b\u003e relies on its insulation details: wide draft tubes run along the main zipper, and a massive thermal collar prevents warm air from escaping from the upper chest. The \u003cb\u003e650 cuin duck down\u003c\/b\u003e ensures even heating. The \u003cb\u003e3D footbox\u003c\/b\u003e provides the necessary space for your feet without compressing the down. The outer \u003cb\u003e20D nylon\u003c\/b\u003e stands up without flinching to the harsh life inside a tent in cold weather.\u003c\/p\u003e\n\u003cp\u003eHowever, if the winter season is coming to an end and you are looking instead to equip yourself for mild to cool spring and summer nights with an ultra-minimalist carrying philosophy, the profile of the \u003ca title=\"See the 3-season Aegismax Mini model\" href=\"\/en\/products\/sac-de-couchage-10-degre-aegismax-mini\"\u003eAegismax Mini\u003c\/a\u003e will be the ideal starting point to lighten your pack.\u003c\/p\u003e","brand":"Ma boutique","offers":[{"title":"L","offer_id":52587868520785,"sku":"14:200006153#SP1000 L Brown","price":359.0,"currency_code":"EUR","in_stock":true},{"title":"M","offer_id":52587868651857,"sku":"14:193#SP1000 M Brown","price":359.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/sac_de_couchage_-10_degr_s_naturehike.webp?v=1767131134"},{"product_id":"sac-de-couchage-grand-froid-aegismax-g5","title":"Extreme cold sleeping bag (-23°C) | Aegismax G5","description":"\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eWeight:\u003c\/b\u003e 1,768 g (Regular) \/ 1,878 g (Long)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eDimensions:\u003c\/b\u003e 196 × 78 cm (Regular) \/ 216 × 82 cm (Long)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eComfort temperature:\u003c\/b\u003e -23°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eLimit temperature:\u003c\/b\u003e -30°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eFill:\u003c\/b\u003e 800 cuin white goose down, RDS certified\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eOuter fabric:\u003c\/b\u003e DWR water-repellent 15D iFlex® nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eThermal standard:\u003c\/b\u003e EN 13537\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003eExpedition sleeping bag for extreme environments\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eAegismax G5 extreme cold sleeping bag\u003c\/strong\u003e is a critical piece of equipment designed for mountaineers and winter bivouac enthusiasts. When the thermometer drops below -20°C, there is no room for error. This model utilizes an exceptional density of \u003cb\u003enatural down\u003c\/b\u003e to create an impenetrable insulating barrier, capable of maintaining your \u003cb\u003ebody temperature\u003c\/b\u003e at a safe level throughout the night.\u003c\/p\u003e\n\u003ch3\u003eThermal engineering and elimination of cold spots\u003c\/h3\u003e\n\u003cp\u003ePerformance at these temperatures relies on a strict architecture: \u003cb\u003ebaffled construction\u003c\/b\u003e that prevents the \u003cb\u003eRDS-certified 800 cuin down\u003c\/b\u003e from shifting to the extremities. The anatomical footbox and the ultra-covering insulated hood lock in areas of high heat loss. The \u003cb\u003e15D iFlex® nylon\u003c\/b\u003e shell, treated with a water-repellent finish, effectively protects the down from condensation inside the tent, ensuring constant \u003cb\u003eloft\u003c\/b\u003e during prolonged exposure to freezing conditions.\u003c\/p\u003e\n\u003cp\u003eFinally, if your expeditions involve technical mountaineering at -30°C and extreme gear weight reduction is a matter of safety, the ultralight engineering of the \u003ca href=\"\/en\/products\/sac-de-couchage-grand-froid-moins-30-aegismax-ultra\" title=\"Discover the Aegismax Ultra -30°C\"\u003eAegismax Ultra\u003c\/a\u003e model will allow you to drop below the 1.6 kg mark while maintaining absolute warmth.\u003c\/p\u003e","brand":"Duvet Nomade","offers":[{"title":"G5 \/ Regular","offer_id":52897975927121,"sku":"14:29#G5-Regular-Blue;200007763:201336100","price":699.0,"currency_code":"EUR","in_stock":true},{"title":"G5 \/ Long","offer_id":52897975992657,"sku":"14:366#G5-Lengthen-Blue;200007763:201336100","price":699.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/AEGIS_G5_01.webp?v=1774707857"},{"product_id":"sac-de-couchage-grand-froid-aegismax-d5","title":"Extreme cold sleeping bag (-17°C) | Aegismax D5","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eWeight:\u003c\/b\u003e 1,768 g (Regular) \/ 1,878 g (Long)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eDimensions:\u003c\/b\u003e 196 × 78 cm (R) \/ 216 × 82 cm (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eComfort temperature:\u003c\/b\u003e -17 °C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eLimit temperature:\u003c\/b\u003e -25 °C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eFill:\u003c\/b\u003e 650 cuin white duck down, RDS certified\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eOuter fabric:\u003c\/b\u003e 15D DWR water-repellent nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cb\u003eThermal standard:\u003c\/b\u003e EN 13537\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003eExtreme insulation for demanding winter bivouacs\u003c\/h2\u003e\n\u003cp\u003eDesigned for harsh environments, the \u003cstrong\u003eAegismax D5 extreme cold sleeping bag\u003c\/strong\u003e is a true thermal barrier for expeditions in freezing conditions. Achieving a comfort temperature of -17 °C requires a significant volume of fill, expertly distributed within a snug mummy fit. This \u003cb\u003ewinter sleeping bag\u003c\/b\u003e drastically limits body heat loss, ensuring a secure night's sleep when the cold settles in for the long haul.\u003c\/p\u003e\n\u003ch3\u003eThermal barrier and insulating finishes\u003c\/h3\u003e\n\u003cp\u003eThe effectiveness of this model relies on crucial details: an ultra-enveloping multi-chamber hood, an imposing thermal collar, and a draft tube positioned along the zipper. The \u003cb\u003eRDS-certified 650 cuin down\u003c\/b\u003e maintains its structural integrity even after several days of compression. The \u003cb\u003eDWR nylon\u003c\/b\u003e outer membrane blocks frost and moisture, ensuring absolute reliability of the down in hostile environments.\u003c\/p\u003e\n\u003cp\u003eTo face even more extreme temperatures (-23°C) without weighing down your pack or pulk, transitioning to the premium goose down fill power of the \u003ca href=\"\/en\/products\/sac-de-couchage-grand-froid-aegismax-g5\" title=\"View the Aegismax G5 extreme cold\"\u003eAegismax G5\u003c\/a\u003e model will be the appropriate technical solution.\u003c\/p\u003e","brand":"Duvet Nomade","offers":[{"title":"D5 \/ Long","offer_id":52897976582481,"sku":"14:100013777#D5-Black-Lengthen;200007763:201336100","price":429.0,"currency_code":"EUR","in_stock":true},{"title":"D5 \/ Regular","offer_id":52897976615249,"sku":"14:200006156#D5-Black-Regular;200007763:201336100","price":429.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/AEGIS_D5_02.webp?v=1774707272"},{"product_id":"sac-de-couchage-grand-froid-naturehike-snow-petrel-pro700","title":"Extreme cold sleeping bag -11°C | Naturehike Snow Petrel PRO700","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eWeight (size M):\u003c\/strong\u003e 1,070 g (bag only) — 1,250 g with storage bag\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eComfort temperature:\u003c\/strong\u003e -11.1°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eLimit temperature:\u003c\/strong\u003e -19°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eThermal standard:\u003c\/strong\u003e GB\/T 38426\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFill:\u003c\/strong\u003e 90\/10 white goose down — 750 FP — 660 g (size M)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eOuter fabric:\u003c\/strong\u003e 10D nylon with durable water repellent (DWR) treatment\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eCompressed volume (extreme):\u003c\/strong\u003e 24 × 25 cm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAvailable sizes:\u003c\/strong\u003e S (\u0026lt; 170 cm) \/ M (\u0026lt; 180 cm) \/ L (\u0026gt; 180 cm)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDown certification:\u003c\/strong\u003e RDS (Responsible Down Standard)\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003eHigh-cold down sleeping bag for winter bivouacs and high-altitude treks\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eNaturehike Snow Petrel PRO700 high-cold goose down sleeping bag\u003c\/strong\u003e is designed for nights below -10°C: winter mountaineering, high-mountain bivouacs, and 4-season hiking in the Alps or Pyrenees. The \u003cb\u003ecomfort temperature of -11.1°C\u003c\/b\u003e is measured according to the GB\/T 38426 standard. Below the \u003cb\u003elimit temperature of -19°C\u003c\/b\u003e, the bag enters the danger zone: reserved for experienced users who know how to compensate (wearing a down jacket, using a liner). The \u003cb\u003eextreme temperature of -41.8°C\u003c\/b\u003e is a theoretical survival threshold, not a usage indicator.\u003c\/p\u003e\n\u003ch3\u003eConstruction and thermal ratio of the 750 FP fill\u003c\/h3\u003e\n\u003cp\u003eThe \u003cb\u003e750 FP white goose down\u003c\/b\u003e with a 90% down ratio and a cleanliness level certified at 1,000 mm (RDS standard) ensures uniform insulation throughout the bag. The structure with \u003cb\u003eindependent diamond-shaped vertical baffles\u003c\/b\u003e prevents the fill from shifting and eliminates cold spots. The thermal side wall and integrated anti-cold baffle limit heat loss at the zipper. The \u003cb\u003e10D nylon fabric\u003c\/b\u003e with DWR treatment contributes to \u003cb\u003ecompressibility\u003c\/b\u003e (24 × 25 cm under extreme compression) but requires precautions: avoid prolonged abrasive contact with the ground or tent walls. In wet conditions, a \u003cb\u003ewaterproof bivy bag\u003c\/b\u003e is recommended — down loses a significant part of its insulating power if wet.\u003c\/p\u003e","brand":"Duvet Nomade","offers":[{"title":"PRO 700 \/ M","offer_id":53234799673681,"sku":"14:200005536#PRO700-M-Orange;200007763:201336100","price":479.0,"currency_code":"EUR","in_stock":true},{"title":"PRO 700 \/ L","offer_id":53234799706449,"sku":"14:100018786#PRO700-L-Orange;200007763:201336100","price":499.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/sac_de_couchage_naturehike_pro700.webp?v=1772974530"},{"product_id":"sac-de-couchage-grand-froid-naturehike-base1100","title":"Extreme cold sleeping bag -16°C | Naturehike BASE1100","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDimensions (M):\u003c\/strong\u003e 200×85 cm — recommended height under 175 cm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDimensions (L):\u003c\/strong\u003e 210×90 cm — recommended height over 175 cm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eComfort temperature:\u003c\/strong\u003e -16°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eLimit temperature:\u003c\/strong\u003e -25°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eExtreme temperature:\u003c\/strong\u003e -50°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1530g (M) \u0026amp; 1620g (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFill:\u003c\/strong\u003e 650FP water-repellent duck down — 90% down clusters \/ cleanliness 1000 mm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDown certification:\u003c\/strong\u003e Responsible Down Standard (RDS)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eOuter fabric:\u003c\/strong\u003e 20D waterproof, breathable, ripstop nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eThermal standard:\u003c\/strong\u003e GB\/T 38426-2019 and ISO 23537-1\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003eThermal certification GB\/T 38426 and ISO 23537: interpreting values and validity conditions\u003c\/h2\u003e\n\u003cp\u003eThe BASE1100 certifies a comfort temperature of \u003cb\u003e-16°C\u003c\/b\u003e and a limit temperature of \u003cb\u003e-25°C\u003c\/b\u003e according to \u003cb\u003eGB\/T 38426-2019\u003c\/b\u003e and \u003cb\u003eISO 23537-1\u003c\/b\u003e standards, which are measurement protocols using thermal mannequins in standardized conditions. These two standards coexist with identical test protocols: the values are directly comparable between models certified under either reference. The extreme temperature of \u003cb\u003e-50°C\u003c\/b\u003e corresponds to the theoretical survival threshold defined by the standard, applicable only in emergency situations with full equipment. In field conditions at this range, a sleeping pad with an \u003cb\u003eR-value greater than 5\u003c\/b\u003e, a merino base layer, and airtight wind protection are non-negotiable prerequisites.\u003c\/p\u003e\n\u003ch3\u003e650FP water-repellent duck down: 1000 mm cleanliness and RDS certification\u003c\/h3\u003e\n\u003cp\u003eThe filling is \u003cb\u003e650FP\u003c\/b\u003e water-repellent \u003cstrong\u003educk down\u003c\/strong\u003e, with a \u003cb\u003e90%\u003c\/b\u003e down cluster ratio and a cleanliness rating of \u003cb\u003e1000 mm\u003c\/b\u003e certified by a third-party laboratory. The 650FP fill power positions this model below the 750-800FP of ultralight bags: compressed volume and weight are higher for an equivalent thermal fill, offset by a lower production cost and increased moisture resistance thanks to the water-repellent treatment applied directly to the down. The \u003cb\u003eResponsible Down Standard (RDS)\u003c\/b\u003e certification ensures the traceability of the down supply chain, from breeding to processing.\u003c\/p\u003e\n\u003ch3\u003eVertical box construction and 14-stitch\/3 cm down-proof thread: anti-migration and anti-leak\u003c\/h3\u003e\n\u003cp\u003eThe construction uses a \u003cb\u003evertical box structure\u003c\/b\u003e with independent compartments and high-density down-proof thread at \u003cb\u003e14 stitches per 3 cm\u003c\/b\u003e. The vertical box keeps the fill in position without nighttime migration, whereas box-stitch construction creates cold spots at every seam line. Three design points limit heat loss in critical areas: a full-length anti-draft baffle along the zipper, a mummy hood with independent drawstrings, and an \u003cb\u003eenveloping foot box\u003c\/b\u003e insulated in three dimensions.\u003c\/p\u003e","brand":"Duvet Nomade","offers":[{"title":"Blue \/ L \/ 1100","offer_id":53842459984209,"sku":"14:200003699#Base Blue 1100 L;200007763:201336100","price":489.0,"currency_code":"EUR","in_stock":true},{"title":"Blue \/ M \/ 1100","offer_id":53842460180817,"sku":"14:200005536#Base Blue 1100 M;200007763:201336100","price":469.0,"currency_code":"EUR","in_stock":true},{"title":"Grey \/ L \/ 1100","offer_id":53842460148049,"sku":"14:100018786#Base Grey 1100 L;200007763:201336100","price":489.0,"currency_code":"EUR","in_stock":true},{"title":"Grey \/ M \/ 1100","offer_id":53842460213585,"sku":"14:365016#Base Grey 1100 M;200007763:201336100","price":469.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/naturehike_base1100_bleu.webp?v=1779491876"},{"product_id":"sac-de-couchage-grand-froid-naturehike-jv1300","title":"Extreme cold sleeping bag -17°C | Naturehike JV1300","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1.78 kg (M) \/ 1.88 kg (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 87 x 193 cm (M) \/ 87 x 203 cm (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003ePacked size:\u003c\/strong\u003e ɶ27 x 45 cm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFill:\u003c\/strong\u003e 750 FP white goose down, 90% down, 1000mm cleanliness, \u003cstrong\u003eRDS certified\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFill weight:\u003c\/strong\u003e 1300g\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eOuter fabric:\u003c\/strong\u003e 20D Toray nylon, DWR water-repellent treatment\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eLining:\u003c\/strong\u003e 10D down-proof nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eComfort temperature:\u003c\/strong\u003e -17.7°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eLimit temperature:\u003c\/strong\u003e -26.7°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eThermal standard:\u003c\/strong\u003e GB\/T 38426 \/ ISO 23537\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003e1300g extreme cold sleeping bag for demanding winter treks\u003c\/h2\u003e\n\u003cp\u003eThe Naturehike JV1300 is an \u003cstrong\u003eextreme cold sleeping bag\u003c\/strong\u003e designed for demanding winter conditions: high-altitude bivouacs, winter treks, or expeditions in extreme cold. A fill of \u003cb\u003e1300g of 750 FP white goose down\u003c\/b\u003e, 90% down, 1000mm cleanliness, and RDS certification provides substantial insulation within a temperature range measured according to GB\/T 38426 and ISO 23537. The comfort rating of -17.7°C corresponds to a standard user sleeping in a relaxed position. The limit of -26.7°C is the equilibrium threshold for men in a curled-up position. The extreme of -52.7°C is a theoretical survival threshold and should never be confused with the target usage.\u003c\/p\u003e\n\u003ch3\u003eExtreme cold thermal construction: vertical velvet and baffles\u003c\/h3\u003e\n\u003cp\u003eThe \u003cb\u003evertical velvet\u003c\/b\u003e construction keeps the fill in a fixed position within each chamber, eliminating down shifting and cold spots at the seams. The zip baffle blocks cold air infiltration along the \u003cb\u003eanti-snag YKK\u003c\/b\u003e zipper. Anti-wind side strips on both sides reduce heat loss from the flanks. The adjustable collar insulates the neck area. The covered 3D footbox protects the feet without compressing the fill. These features are exclusive to the 1000g and 1300g versions.\u003c\/p\u003e\n\u003ch3\u003eToray 20D fabric and independent laboratory certification\u003c\/h3\u003e\n\u003cp\u003eThe \u003cb\u003e20D Toray nylon DWR\u003c\/b\u003e outer fabric combines tear resistance with surface water repellency. The \u003cb\u003e10D down-proof nylon\u003c\/b\u003e lining limits fill migration. The dual-zip closure allows for arm movement without leaving the bag. Compressed to ɶ27x45cm and weighing 1.78kg in size M, the JV1300 comes with a compression sack and a mesh bag for long-term storage.\u003c\/p\u003e","brand":"Duvet Nomade","offers":[{"title":"M","offer_id":53947869921617,"sku":"14:200004890#JV1300 M","price":999.0,"currency_code":"EUR","in_stock":true},{"title":"L","offer_id":53947869954385,"sku":"14:200006156#JV1300 L","price":999.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0993\/9173\/4097\/files\/naturehike_jv1300.webp?v=1780522020"},{"product_id":"sac-de-couchage-grand-froid-naturehike-ul1100","title":"Extreme cold sleeping bag -21.4°C | Naturehike UL1100","description":"\u003ch2\u003eTechnical specifications\u003c\/h2\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1.59 kg (M) \/ 1.68 kg (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 85 x 200 cm (M) \/ 90 x 210 cm (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eExtreme compression:\u003c\/strong\u003e 24 x 25 cm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFilling:\u003c\/strong\u003e 850 FP white goose down, 95% down, cleanliness 1000mm, \u003cstrong\u003eRDS certified\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFill weight:\u003c\/strong\u003e 1005g (M) \/ 1100g (L)\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eOuter fabric:\u003c\/strong\u003e 10D 500T down-proof nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eLining:\u003c\/strong\u003e 10D 500T down-proof nylon\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eZipper:\u003c\/strong\u003e Anti-snag YKK + double elastic drawstring\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eComfort temperature:\u003c\/strong\u003e -21.4°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eLimit temperature:\u003c\/strong\u003e -31.0°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eExtreme temperature:\u003c\/strong\u003e -58.7°C\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eThermal standard:\u003c\/strong\u003e GB\/T 38426-2019 \/ ISO 23537\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch2\u003e850 FP extreme cold sleeping bag for mountaineering and winter bivouacs\u003c\/h2\u003e\n\u003cp\u003eThe Naturehike UL1100 is an \u003cstrong\u003eextreme cold sleeping bag\u003c\/strong\u003e filled with 850 FP white goose down, 95% down, with cleanliness certified at 1000mm and RDS certification. With 1005g of fill in size M, it is designed for bivouacking in challenging winter conditions where nighttime temperatures regularly drop below -15°C. The temperature range is measured according to GB\/T 38426-2019 and ISO 23537 using an instrumented heated mannequin (report ZINK-LAB2410037). The comfort rating of -21.4°C corresponds to a standard female user sleeping in a relaxed position. The limit of -31.0°C is the thermal equilibrium threshold for a male in a curled position. The extreme of -58.7°C is a theoretical survival threshold. These values assume the use of a sleeping pad with an appropriate R-value.\u003c\/p\u003e\n\u003ch3\u003eTriangular baffle construction and closed channels\u003c\/h3\u003e\n\u003cp\u003eThe \u003cb\u003etriangular baffle construction\u003c\/b\u003e distinguishes the UL1100 from standard square-baffle bags. The triangular geometry keeps each chamber at an independent volume with a reduced contact surface, which limits cold spots at the seams and accelerates loft recovery. The channels are fully closed at both ends to prevent any down migration. The 1100g version includes a \u003cb\u003ethermal side wall\u003c\/b\u003e that insulates the sides, a critical point of heat loss during prolonged winter bivouacs.\u003c\/p\u003e\n\u003ch3\u003e10D 500T fabric and triple storage system\u003c\/h3\u003e\n\u003cp\u003eThe \u003cb\u003e10D 500T nylon\u003c\/b\u003e outer fabric and 10D 500T lining combine down-proof performance with lightness. The \u003cb\u003eanti-snag YKK\u003c\/b\u003e zipper with double elastic drawstring, integrated thermal hood, and zipper baffle complete the peripheral insulation. Three storage systems: long-term storage mesh bag, transport bag, and extreme compression bag 24x25cm. 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