Air Activated And Ready in Minutes- Air- activated heat packs mean that you’re ready for the cold at a moment’s notice. It’s the best way to stay warm with zero prep – no charging needed. Simply open the package, pull on the shirt, and feel the warmth (up to100°F/38°C) heating up your core.

ReSeal and ReUse- The UnderWarmer is disposable. However, If only worn for a few hours, place it in an air tight/ziplock bag and it will stop producing heat. When you remove the UnderWarmer it will reactivate.  

Feel Snug And Gently Stimulated– The UnderWarmer is a soft, lightweight compression shirt. So it feels really, really good. But most importantly, that snug fit means the warmth stays right where you need it – near your skin. (Make sure to use our detailed size chart and diagram to choose the best size to fit your upper body so you get the ultimate UnderWarmer experience.)

Perfect For Cold Weather Activities– You always thought that you had to choose between your favorite winter activity and staying warm. But no longer. Whether you’re deer hunting, tailgating, hiking or camping in the cold outdoors, the UnderWarmer heated bodywarmer shirt will make it a wonderfully warm experience.

Great Gift For Football Fans – Gift your tailgating spouses and buddies (or yourself!) with a way to enjoy cold weather football games AND stay warm.