{"product_id":"modern-needs-emergency-sleeping-bag-thermal-bivy-sack","title":"Modern Needs Emergency Sleeping Bag Thermal Bivy Sack","description":"\u003cp\u003eA \u003cstrong\u003eModern Needs thermal bivy emergency bag\u003c\/strong\u003e is the survival shelter that weights almost nothing but solves the core problem of a forced overnight without sleep system: ground contact loses heat faster than radiation or convection, and wind amplifies losses through evaporative cooling. This bivy's reflective interior bounces your radiant heat back while the outer layer blocks wind and damp.\u003c\/p\u003e\n\u003ch2\u003eModern Needs Compact Thermal Bivy for Survival\u003c\/h2\u003e\n\u003cp\u003eThe thermal lining works through radiation: about 90% of body-heat loss in a survival shelter comes from radiation to the sky and surroundings, not conduction through the ground. Reflective material returns that radiation back at you — the mechanism is proven in emergency space blanket science. The sack format means you don't need to assemble anything — crawl inside and you're sheltered. Modern Needs' design emphasizes packability: this fits in a jacket pocket, lives on a paracord lanyard, or stashes in a survival kit without demanding space. The fabric is waterproof enough for the actual emergency scenario: rain or dew, but not extended submersion.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReflective thermal lining returns radiant body heat\u003c\/li\u003e\n  \u003cli\u003eBlocks wind — the mechanism amplifying heat loss in cold weather\u003c\/li\u003e\n  \u003cli\u003eSack format — no assembly in emergency conditions\u003c\/li\u003e\n  \u003cli\u003ePocket-sized when compressed — lives on a lanyard or in a kit\u003c\/li\u003e\n  \u003cli\u003eWaterproof for rain and dew exposure\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eFor day hikers and backcountry travelers, this is the insurance that fits in a jacket pocket and costs nothing in trail performance.\u003c\/p\u003e","brand":"Modern Needs","offers":[{"title":"Default Title","offer_id":52549437817108,"sku":"PPO-B0CBSR586N","price":12.97,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0894\/6614\/2996\/files\/81VQ29ppWUL-AC-SL1500-_1.jpg?v=1780208368","url":"https:\/\/peakperformanceoutfitters.com\/products\/modern-needs-emergency-sleeping-bag-thermal-bivy-sack","provider":"Peak Performance Outfitters","version":"1.0","type":"link"}