#2 Chemical Packets
These little guys use a thermal chemical reaction to create heat. They come sealed in this plastic bag, when you break them open the interaction with air begins the chemical reaction. When you shake them you amplify this reaction and speed up the process. This process produces heat.
To use these at night, shake up about 6 of them 30 minutes before you’re ready to hop in your sleeping bag. After you shake them up you can toss them into your bag and finish getting ready for bed. These guys produce decent heat when you consider cost and weight but they won’t make a big difference long term throughout the night because the volume of heat is really small compared to the space they are trying to warm up. It will feel more like a hot spot in your hand or on your body somewhere.
Keep these handy all night because they are a one time use and will last less than an hour.
Ok, let’s go over the pros and cons of a chemical hot packs.
- Small, lightweight, and easy to carry
- Simple to use, just shake and wait.
- Great for warming a specific area - like your hand
- Isolated heat at best, not going to provide serious relief.
- It is in fact a chemical reaction happening next to your skin. Whatever that means to you.
- Single use, these are going to be thrown away after about a 45minute lifespan because after that they are just dead weight.
Summary, they’re easy to get going, much more comfortable than rocks, but they are tiny and single use - so you’ll need a lot of them throughout the night and will have to pack them out.