As I am typing this the temperature is around 0F. Having lived in Minnesota for over 20 years I know a little something about cold hands. From hunting, ice fishing and other recreation outdoors, to employment and jobs around the homestead that requires you be outside in all conditions, you learn how to keep your hands warm. In this review I will cover 3 types of hand warmers I use, the pros and cons and what situations I use them in. All links in this post are affiliate links to Amazon. I own and use all of these products, but we do get a little kickback if you purchase through my link.
Element Thermocharge by Celestron 2 in 1

I got a couple of these a while back for Christmas and immediately fell in love with them. They are small, dual purpose and work surprisingly well after a little learning curve. It serves as both a hand warmer and a battery backup for small electronics such as a cell phone. They are fairly cheap at about $30 on Amazon as of this posting. At full charge it holds 4400 mAh of energy to either provide heat or backup power. That is enough to charge my Galaxy S21 Ultra just under one time. In a pinch that can be pretty handy to have. I keep one charged up in the summer for just that reason. Its the winter though that this product really shines.
The product listing says it will provide 6 hours of heat if it is left on. I am not sure how accurate that is but I don’t leave it on all the time. This type of hand warmer I use for quick warmups. If I am out doing something that I can use gloves most of the time, or keep my hands in my pockets, I will use this to “take the chill off” or warm my hands if I take off the gloves or out of the pockets. It has 2 heat settings and depending on how cold it is I will turn it on high or low for a couple minutes while holding it in my pockets. This is normally enough time for it to heat up, warm my hands and also warm my pockets. I then click it off and either put my gloves back on or keep my hands in my pockets. Using this short burst method I routinely get a long day hunting or ice fishing out of one charge.
Zippo Refillable Hand Warmer

These things are great for all day (and sometimes longer) steady heat. You basically fill the wick inside with lighter fluid and light it up. Blow out the flame and it kind of smolders all day. There is a nice bag for it that also warms up. I have lit these on hunting trip and still had it be nice and hot the next morning. It comes with a little container to measure and fill the lighter fluid. They currently run about $16 and you can pick one up Here.
Hot Hands Old School Hand Warmers

The last type of hand warmer I use is the old school air activated ones. HotHands seems to be a pretty good choice when using these. Open the package and expose to air and the chemical reaction starts to heat them up. I never count on them to much and have extra incase of a failure. Get them warm and you can throw them in your shoes, pockets, jacket, hat, underwear, anywhere. Bonus use is as an O2 absorber when storing food in buckets. They are also the cheapest option with a package of 40 pairs (80 hand warmers) coming in around $27 on Amazon
Keeping your hands and feet warm can be a challenge but hopefully with one of these choices you can stay nice and comfortable: