Re-usable hand warmers?

Question

I have got a pair of those re-usable hand warmer things - the liquid filled ones with the metal switch inside them. When you press the switch, the liquid turns sort of solid and heats up to keep your hands warm. It tells you to place them in boiling water for a short period in order to re-use them. I assumed that they would go back to the way that they were when I first bought them, and you would press the switch again ito get them to heat up, but instead, it turns to liquid again at first, but seems to go solid again as they cool.

Am I doing something wrong? Or is the boiling water simply intended to heat them up to be re-used there and then. Does anyone know if there is a way to reuse them by pressing the switch to activate the heat?

Do I place them in a bowl of boiling water then, or would you advise boiling them in a pot?

Answer 1

This is the instructions from the hand warmers i have
1.Bend metal plate.
2.The saline solution inside the pocket warmer s will crystallise.Depending on the outside temperature.your pocket warmers will give up to 55 degrees heat for 1 hour.
3.As the hand warmers cool down the saline solution becomes hard.
Before using the warmers again put them into boiling hot water until the contents are completely clear and fluid( approx 10 Min's).Thereby wrap the warmers into a towel forr protection.Attention: let the warmers cool before picking it up or removing it.Now you can activate the warmers again by bending the metal plate.
This is off the pack i have hope this helps.they really are handy little things especially fo the kids.

Answer 2

How long are you leaving the them in the boiling water? It needs to be around 10 - 15 minutes depending on the size of the warmer. If there are even a few solid crystals in in the pouch then it will start to solidify again immediately as it cools. Try shaking the pouch a little half-way through the boiling time to make sure the gel is even distributed & heated to melt all the crystals.

Edit to add:

Yes, boil them in a pot of water.

I've found this link from a manufacturer for you:

http://www.warmitup.co.uk/instructions.htm

Answer 3

Depending on what hand warmers you have got they have instructions on them. Some say heat in boiling water for 5 Min's, some say 10 Min's. In any case you should be leaving them until the crystals have dissolved. They then work by pressing the metal disc.

Answer 4

I've heard of those re-usable's If I'm not mistaken the "switch you refer to is a thin metalic disk that is somehow bended occasionally to activate the solution for heat. There supposed to be good for a few moments of heat and thats about it! Your better off with the "air-activated" disposables in that as you take them out of their cellophane wraper the oxygen "activates the chemicals and it produces heat. Just be careful with these chemical types!! They do work for many hours when you insert them into a glove shell and you wear an inner glove to protect your hand. Best solution...Keep your hands DRY! wrap them in layers just as you would the rest of your body.

Answer 5

We used the same things in the Ambulance Sevice you have to make sure there are no crystals left afte heating and leave them to cool,then they can be stored for reuse in the normal way.

Answer 6

I don't think you are leaving them in the water long enough. Depending on the instructions tell you, check them out.

Answer 7

Hiya the switch only works once Im afraid- after that its literally just putting them in hot water to reheat the gel- thats how you reuse it. Its a shame cos the switch thing is cool! But ones its popped thats it!

Answer 8

Pockets are re-usable hand warmers, and they seem to be easier to use than what you have.