A Hot Pack yields almost an hour of steady, finger-reviving warmth once activated. Or if you're not too keen on showing the cold getting to you, just leave it in a pocket close to your body for a blast of secret, relatively-high temperature pleasure.
The concept is very simple. Inside the tough plastic shell of a Hot Pack is a thick, clear liquid and a small metal disc. 'Click' the disc and you start a chemical reaction which heats the liquid to a toasty 130F in about five seconds. That's very fast.
Once warm, the Hot Pack remains at a constant temperature for roughly 25 minutes before losing its power of heat. After use, the liquid will have solidified, and all that's required to regenerate a Hot Pack is to heat it in a pan of boiling water until the solid turns back into a liquid. Boil-in-the-bag hotness magic.
There are plenty of times one of these will come in, ahem, handy. On the touchline, on the journey to work, those romantic winter walks accompanied by classic hits during movie montages and many more. Quite simply, warm hands are better than cold ones. Ask any man who's had to drop 'em and cough...