· They Heat up on their own
· Provides heat, simply click the metal disc
· Instant portable and reusable heat
· No Microwave needed
· Safer alternative for hot water bottles & Smelly Wheat Bags
· No fire hazard or overheating
· Can also be used as a cold pack
· Nationwide 12 Month Warranty
Click'n'Heat Packs contains sodium acetate and water. It turns out that sodium acetate is very good at supercooling. It "freezes" at 130 degrees F (54 degrees C), but it is happy to exist as a liquid at a much lower temperature and is extremely stable. Clicking /Flexing the patented stainless steel "trigger", however, has the ability to force a few molecules to flip to the solid state, and the rest of the liquid then rushes to solidify as well. The temperature of the solidifying liquid jumps up to 130 degrees F in the process.
To understand super-cooling, imagine a glass of water at 0ºC or 32ºF. It should turn into ice. This phase change, from one state (liquid) to another, (solid or crystals) occurs with a change in temperature. If the water dropped below 31ºF and no phase changed occurred, the water would be considered a super-cooled liquid.
When the heat pack is triggered, the solution crystallises, and the temperature immediately jumps back to its "freezing" point. Much in the same way the water crystals produce "heat" at 0ºC or 32ºF, the heat pack produces an even heat flow with the crystals it produces at higher temperatures.
By being able to control super-cooled fluids, the system can produce heat for two to three hours (or longer) depending on the size of the bag and the insulation used. Duration of time and temperature of the packs can be varied to meet many application demands.
Once the unit has given off all of its heat, it is then recycled by heating it up. The easiest method is by boiling in water for 5-15 minutes, depending on the product size. The product is heated, melting the crystals back to a liquid state and then is allowed to cool below its freezing temperature.
When you boil the solid heat pack you melt it back to the liquid state. You have to completely melt every crystal, by the way, or the liquid will quickly re-solidify. You can repeat this cycle forever, theoretically, just as you can freeze and melt water as many times as you like. It is then ready to be activated again anytime anywhere. The solution is completely safe (since sodium acetate is a food additive, it is non-toxic).
For those of us who love the great outdoors but like a few little creature comforts the camper pack is brilliant. Like all our heat packs this is a totally portable, totally easy to use pack. The hand warmers are hugely popular with campers and fishermen alike and the fact that you can access strong even heat whenever and wherever you are, is a winner with all.
2 X sports heat pack
4 X pocket warmers