Grabber Hand Warmers, 10 pairs. These rectangular, single-use heat packs keep your hands warm and toasty on the coldest days of the year. Air-activated hand warmers work by simply shaking the pouch and will keep your hands warm for up to 10 hours. They are perfect for hunters, campers, skiers, and anyone else who spends extended periods of time outdoors. Average temperature of 135 degrees F. Made in the USA.