In any season and all types of weather, stay warm and dry with the lightweight, durable SOL Emergency Thermal Bivvy. Fully windproof and water resistant, the bivvy provides extreme warmth and protection with a metallized coating that reflects 80% of body heat, preventing heat loss by trapping warm air against your body while keeping the elements out. The bivvy sleeping bag is durable and resists punctures and tears from heavy use and includes a tindercord drawstring for emergency fire starting with a built-in rescue whistle for emergency signaling. For heat regulation and climate control, the footbox and hook and loop closures allow for adjustable ventilation. The multipurpose bivvy can be used as a sleeping bag liner or as a heat-reflective blanket in extreme cold.