Hand warmers can be a game-changer when you’re heading out into chilly temperatures. Once, while visiting the infamous snow monkeys in Japan , my fingers got so cold that they wouldn’t register on my phone’s touch screen. Without gloves or hand warmers, I ended up leaving early to warm my frozen digits with a cup of hot tea. Trust me, having to leave an epic experience—or needlessly suffering through it—because of cold temperatures will quickly ruin your day.

Whether you’re looking for a temporary on-demand heat source or need to keep nimble during a cross-country ski outing , hand warmers are always a good idea.…