The UnderWarmer® is a single-use, compression fitted HEATED base-layer shirt for cold weather activities. 8 HEAT PACKS are built-in and will activate within minutes of removing from its packaging, staying warm for over 10 HOURS

When ready to use, simply remove The UnderWarmer® from its packaging. Upon opening, heat activation begins and will take approximately 30 minutes for the heat packs to reach its maximum temperature.

The UnderWarmer heated base-layer shirt is safe to wear directly against your skin.

Headed Outdoors or To The Game?… Better Get an UnderWarmer!!!


We like to say, The UnderWarmer® will help you embrace the cold outdoors!

From soccer moms to serious deer hunters, any cold weather situation is perfect for The UnderWarmer®

It’s a no brainer.

Jeff Pfeifer, Avid Outdoorsman
Loved it .. kept me warm the whole day ..
I’ll be wearing one to every cold game this season!”
Riley Reynolds

The UnderWarmer® – $14.99 w/FREE GROUND SHIPPING!

The UnderWarmer® is designed to fit many body types.
We’ve provided some detail of our models height and weight to help you decide what size will fit you best.