Whether you need 12 hours of reliable heat from a rechargeable warmer like the OCOOPA UT3 PRO or the classic ease of our top pick, the disposable Ignik Hand Warmer ... of muck boots, or a muff.

They’re less adjustable, though. The Ocoopa UT3 Lite rechargeable hand warmers are sold as a pair, which is useful, since you have two hands and might want them equally warm without paying double.