I went to the Arizona State fair about two years ago and found this man selling these absolute gems, I believe I paid 7 or 8 dollars US for them each. They are a clear liquid sealed in a thick soft plastic and there is a "button" inside the liquid and when the button is "snapped" a chemical reaction happens and these crystals start to form in the clear liquid. It kinda looks like highly viscous salt water when the reaction is done and it is very plyable in your hand. Now let me tell you, this thing gets HOT, almost to the point to where it burns your skin to the touch (130 degrees Farenheit). It takes about an hour or so for it to cool down and then it hardens. The coolest thing about these things is that you can boil them for about 5 minutes and they return to liquid again! You can re-use it for hundreds of times! Get more info here: http://www.reheater.com You will love these things, I stuck two of them in my MAIN first aid / survival kit and I thought I would share the resource with you all.

Welcome to the forum Stephen. Yes reheaters work well, i have had mine for a few years. Although i don't have an excuse to use it very often in Florida. If you are looking for a cheaper alternative Walmart sells a copy, it's orange instead of green, in the sporting goods dept. I have not bought one so i don't know if it is as good as the reheater brand or not.

Thanks for the welcome Ray, I know what you mean about not needing a use for them in warmer weather as I am from Houston, TX and now live in Arizona! They are great for an injury, I suppose. When I go camping up north, they can come in handy as well. I will keep an eye out for the WalMart copies, thanks again.

cyko: Generally, for first aid I would discourage the use of heat for any injury unless you specifically know what you're doing. Applying heat to an injury caused by a blow may give short-term relief (hence it's a favourite treatment of athletes) but can cause complications (I believe it causes calcification in the injured area.) <br><br>For hypothermia, warmth should be applied; that can be a problem even in Arizona, especially if the casualty is elderly, ill or in shock.<br><br>In short, I would recommend that heat pads in first aid should be used for keeping a casualty warm, but generally not for treating an injury.