These are the re-usable hand warmers, when they are in liquid form you click the metal disc inside the liquid and the liquid then turns solid and hot, to reactivate them you have to boil them or put them in the microwave (check the instructions first though as this may not be the case for all types/brands). The cost about 3 each and you can get them from Ebay and most sporting/fishing/skiing shops
These are the disposable warmers, they come in pairs and are also known as teabags, to activate you open the packet and just shake gently, they react to oxygen and go hot, they should stay hot for about 7 hours, they are smaller so can fit into gloves and boots. They are far cheaper on Ebay and you can get 10 pairs for about 10 including postage, the more you buy, the cheaper they are. 
They do need a bit of a shake to reactivate them if they have been active for a while.

Click here to return to the main page