HeatMax Survival Heat
The Heatmax Survival Heat Pack is a large 9 by 13-inch warmer that provides up to 15 hours of heat. The Survival Heat pack comes with a new reflective inner liner for emergency signal use, and cold weather survival tips on the back and inside. This warmer is perfect for sleeping bags and is a must-have in a vehicle emergency kit. All Heatmax warmers are made of natural materials, including iron powder, water, salt, activated charcoal, and wood fiber. When exposed to air, these materials react together to produce heat through an extremely fast oxidation (or rusting) process. Users should allow 10 to 20 minutes for the warmers to reach their optimal temperatures.