A couple of years ago I purchased some HotSpot reusable hand warmers from Emergency Essentials. Similar reusable hand warmers are available from other sellers and on Amazon
What are reusable hand warmers?
These hand warmers are a plastic pouch filled with liquid (usually sodium acetate) that creates heat as it crystallizes. Wikipedia has a little more information on how the chemical reaction works. The HotSpot warmers are approximately 3 inches by 5 inches and a little over 1/2 inch thick.
Here’s how they work:
Your hand warmer is supposed to be stored in liquid state and it has a little metal disk floating around inside it.
Grab that little disk and flex it (it doesn’t have to flex much) to start the chemical reaction. This part is really cool. It forms crystals starting at the disk and as they spread, the hand warmer heats up. Watch the video below to see how it works.
The hand warmer reaches a peak temperature of about 120 degrees in the first five minutes. It stays warm between an hour and an hour and a half. Kneading the crystals and keeping the hand warmer in an insulated place like a pocket increases the duration of heat output.
When the hand warmer has cooled, it needs to be reactivated so it can be used again. To reactivate your hand warmer, wrap it in a rag and put it in hot water. The rag is so it doesn’t melt touching the side of your pot.
Bring your water to a boil and boil until all the crystals have disappeared.
When the liquid is all clear, take the hand warmer out of the water and let it cool. It stays pretty warm for a while after being boiled, so you could use it to keep warm again while you’re waiting for it to cool.
Pros and Cons of Reusable Hand Warmers
Pros:
–Reusable
–Heats quickly
–Cost over time is less than instant hand warmers
Cons:
–Must be stored above freezing so they can’t be kept in a car kit or emergency kit that will be exposed to extreme temperatures
–Bulky–they won’t slip into your gloves, but they are fine in a pocket
–Have to be boiled or heated to be used again which could cause problems if you’re using them “in the field”
–Heat only lasts 1-2 hours compared to 8-10 hours for disposable hand warmers
–Initial cost (ranging anywhere from $1.99 to much higher depending on the brand and size) is as low as 4 times what the disposable handwarmers cost.
Uses for Reusable Hand Warmers
Reusable handwarmers are fantastic for short outings, trips to the bus stop, yard work, sporting events, etc. If you’re heading out for a longer outdoor excursion, you’ll want to take one for approximately each hour you’ll be out then reactivate them all when you get back.
They also work great as instant heat packs for medical use.
Perfect for a little gift or stocking stuffer.
For me, the bulkiness and boiling requirement preclude them from being included in my emergency kit, but we own them and use them frequently around the house.
So there you have it. Everything you ever wanted to know about reusable hand warmers.