Mystical 12 Hour Heat Pack - Pocket Disposable Hand Warmers Gloves For Hiking, Camping, Kids, Adults, Backyard, Sporting Events- 25 Pack Used by professionals all over the world. Ultra thin and ready to use. Warms up to 65 degrees Celsius/ 149 degrees Fahrenheit. Lasts up to 12 hours. Great for outdoor use or where ever cold temperatures are expereinced.