Reusable hand warmers are pretty neat

This was an unexpected hit! I found out about these at an outdoors show several years ago, and I was completely fascinated with them. I spent like 20 minutes at the booth and ended up buying some. I just got some more and my roommate has been quite entertained.

Yay heat pumps next time. I know super basics about how they work, but I just bought a house with one and it's scared the hell out of me at least once (it has a defrost mode that's terrifying) and confused me multiple times. I'm really looking forward to it.

Alex Smedberg

How many hundreds of human chests do you suppose will need to be irreparably scalded before the research is complete? I will collect the feedstock.

Kirsa

Was the source of the crystals from the metal bauble? Perhaps the shape of it was deformed in some way leaving it always activated.

Kirsa

That's really cool, I am looking for a way to store heat energy using thermal mass so the inanimate photosynthetic organisms can grow year round in the growing enclosure, I want to use unidimensional parabolic photon concentrators to heat a metal pipe full of fluid (perhaps viscous sodium acetate trihydrate?) and store that energy for the cold time when the planet's axial tilt restricts my personal photon supply. I have seen videos of people who have insulated a large mass of dirt rock and put tubes for air or liquid heat exchange within. I wonder where the bulk distributor of sodium acetate trihydrate lives and what they may ask for in trade. Thank you for this learning, I will carry it with me and spread it to others.

Kirsa

Thank you for this learning, i will carry it with me and give it to others.

Kirsa

Have you tried those fuel hand warmer? Zippo makes them along with some Japanese brands. How it works is also pretty interesting!

Zhenbang Xiao

I think these things would be great for breast implants. On second thought, the reusability process would be prohibitive. We simply need more research in this direction.

If you feel like putting a video on Connextras that's just the footage hot hands hand warmer's contents turning rusty, I would be here for that.

Hodgkin LeBlanc

I've read Cat's Cradle, and I know ice-nine when I see it. Whatever you do, don't open the pouch!

Am I having Dejavu or did you do a video about these like a couple years ago?

Jesse G. Donat

I have seen these before, but they're still really interesting. I haven't seen one in decades.

Kaz Redclaw

I saw a video that used this as a way of miniaturising a hot water tank, not that I seen any on the market yet. Sodium acetate trihydrate can store enough latent heat to provide about 3 times its volume of hot water using a heat exchanger.

Seán Byrne

I had not heard of these hand warmers. Thanks for the information! Any thoughts on reusable "catalytic" warmers like those sold by Zippo? https://www.zippo.com/pages/getting-to-know-the-zippo-hand-warmer

Dre

The same. Only in Russia, in the early 1990's.

Andrey Pivovarov

I ran a first-aid station at a medieval recreation event. I bought 100 of these things (they were clear, cheapish (~1.5 each) and I didn't expect to get any back (I did get back about 20 of them, so good on the good gentles). I agree with Alex that a) The concentrated heat from a solid source is better than the rusty handwarmers) and b) These really aren't worth keeping around. I found that road bumps would set them off. (Luckily the events had food, so boiling water was in plentiful supply.) and finally c) These things are just super-neato cool!

Mike Bird

I give this 2 chemistry PhD thumbs up 👍🏻👍🏻

Retro Game Club podcast retrogameclub.net

I bought once a set of red ones, heart-shaped, for my girlfriend. She found them very heart-warming ;-)

MrHammond

Yep. I've seen them in outdoor stores and camping supply stores.

Craig P Steffen

When supercooled water freezes suddenly, it does the exact same thing. This happens every winter here, where I've left a water bottle in my car overnight and in the morning it's still liquid. A quick shake makes it simply slushy. Never thought to take a thermal camera to it... Unfortunately, 0C/32F is not a useful temperature for hand warmers.

Quinton Wilson

We've picked up some of these after seeing them at a mall kiosk ~20 years ago. I've seen lots of varieties of these now usually sold as muscle relaxers with larger shapes suitable for that.

Marc Chametzky

I haven't watch the video yet, but I've found out about this a couple years ago, and wanted to know more, it's a very fun project to make you own in a sealable freezer bag.

Vlycop

Oh nice! Growing up in Michigan these were the best novelty. I was the coolest kid on the school bus. Great video!

Leo Herzog

I've used these for pain relief, they are quite handy in certain situations, like traveling. When I can, I use a wheat bag/pillow that I heat in the microwave, but don't always have access to a microwave. Don't try leaving them in the car though... I thought it was a great idea 'just in case' I needed a heat pack while out & about - next time I looked in the glovebox it was solid, I guess it got too hot in the car and re-melted itself then froze immediately? I also found that after a while, they stopped re-setting properly and would just crystalise as they cooled. Maybe they got a small leak and water got in and messed up the ratios?

Emily Travis

The reusable heat pad that releases heat by freezing: "SAFETY INFORMATION DO NOT ... freeze".

Very informative. We were given some as part of an apology for a power-cut, and I always wondered how they worked. There was also a wind-up torch (which actually works) and a blanket and a plug in phone (many people only have wireless phones which don't work in power-cuts). That was Scottish Power, and I must admit I was quite impressed, as the cut wasn't really their fault.

Jim Hewlett

These are fairly common in France, I had some as a kid. Luckily, my parents were able to explain to me how they worked, but I'm sure otherwise it would've seemed like magic! I've never heard of the rust ones though :o

Pimellon

Down south, these aren't a thing, but I've heard of them. Enjoyed the video though. Sometimes you end up picking a topic I'd never thought much about and after watching, I learn something new :)

Jason Wellband

In Germany they're quite common too and are (more specifically were) sold in a lot of stores (were, because electric ones are displacing the salt powered ones)

By extension, now I understand why the MRE heater generates heat when combined with water. Rust!

As others have said, other way round in the UK, the reusables are relatively common, never seen the 'rusty' ones before! Both of them are 'cool' though ;). When I was a kid though we generally used the 'charcoal stick' type (slow burning charcoal in a case). Another interesting one is the 'Peacock warmer' (japanese in origin) which uses lighter fluid (benzene) and platinum catalytic reaction. They kind of look like a big Zippo (and googling, seems Zippo also make a similar device!), these stay warm for hours and are what I use now if I need a hand warmer.

Paul Sharp

You can buy these practically everywhere here in the UK. However, I've only ruined ONE pan so far by forgetting it was boiling to "refresh" them!

Brad Jones

I remember getting these in the gift pack one year with my rugby season ticket at the first game. Pretty fun for a few goes then the novelty wears off.

Brian Condron

Poke: I had one of these things (Sodium Acetate warmers) back in 1999 it was mesmersising but ultimately too fiddly with having to boil it to "recharge" it. They got cheap and mass-produced a few years afterwards and were everywhere, only to basically vanish again in recent years.

Anton

I guess you've seen the movie Zack and Miri make a porno? In regards to place the heat packs somewhere on bare skin... *snickers* :D

Anders Enger Jensen

I'm a fan of my USB hand warmer — it's fully reusable, no boiling water required, and I can turn it on and off at will! As someone who gets cold hands, without necessarily spending hours outdoors, it's a real lifesaver. :)

Tuesday M

This made me think of the cold packs that I've seen in sporting equipment. You break a capsule inside the bag, then shake them, and they get really cold. I imagine that they use the same principle, but they do the phase change in the opposite direction.

Michael Dunn

Those are pretty neat, I've never seen them before. I just bought a battery-powered heater that fits in your palm and I'm disappointed with it. It takes 3 hours to charge, but only generates heat for 2 hours, and it isn't really _that_ hot. I'll probably keep it though, since it has a decently-bright flashlight. My favorite reusable heater is a pouch full of something that feels like rice. You zap it in the microwave for a couple minutes, then lay it across the back of your neck or wrap it around your hands or whatever.

Michael Dunn

Harvey's comment on YouTube is amazing. What a great video!

Stavro

Funny, this is the second time I’ve seen these this year. I bought a couple the other day at a local sporting goods store. Prior to that, I haven’t seen one of these for about 30 years. We used to carry these in Boy Scouts during winter camping. For scouts, it was not uncommon to have boiling water around (especially during the winter) so reactivating them was never much of an issue. Thanks for the explanation and a blast to the past.

I would like to point out one very specific use for these, by the way. If you need to get blood drawn - especially if that's something you have to do often - you can use these to get a lot of heat into them, stimulating vasodilation and making the whole process a lot less unpleasant. That's one (admittedly niche) case where you really want a lot of heat for a short amount of time.

They've been in drugstores in the Pacific Northwest since at least the 1980s, FWIW.

Ken McGlothlen

NEAT. i got talked into some awkward demo of the big packs once and wondered how they worked.

evistre

I had a system down! Cold water in the laundry sink and the pot at the ready! Though it was used more for B-roll than the talking head

Technology Connections

Considering how much effort it is to actually reuse these, just casually clicking one in the middle of your script is quite the power move.

dociouscalifragilistic supersaturation, from supercalifragilisticexpialidocious

Dendriti

Geez, what was that long word at 4:36? I can't seem to think how it would be spelled, lol.

in my (tropical) country, we use stockings full of rice heated in a double boiler.

Dendriti

Oddly, if you look on Amazon, the single use ones prevail. But if I go to a shop in the UK, I'm pretty sure I'll only find the reusable ones.

Kirk Northrop

Nice video! These are very common in Europe. I haven’t seen the non-reusable ones though. Maybe in Europe we have the reusable crunchy ones because the single-use powder ones aren’t allowed here?

I also enjoyed the toaster video vibes of more and more heat pads arriving as time goes on...

Kirk Northrop

Of course you upload a video about handwarmers while I'm on the job in a bloody busshelter in -4C and have forgotten to boil mine... Oh well, looking forward to watch it when I'm off duty. They are available in some supermarkets here in Scandinavia, which shouldn't be surprising.

Oscar Røhling

Honestly? In this case I feel like the disposable ones may win when it comes to environmental impact. They also last a long time compared to the acetate ones - 8 hours is perfectly reasonable. And, for what it's worth, the company that makes the one I featured here seems to be Japanese

Technology Connections

This whole continental divide thing is annoying... anyway I hope it's an enjoyable video!

Technology Connections

I love those too. I have seen tons of them. Often they’re used as promotional gifts. Weirdly, I’ve never seen the non-reusable ones. Which just confirms my suspicions that Americans love things that need to be thrown away after use…

I used to have a couple of these.

Brett Walton

These are a classic here in sweden

Braxen

Those things are everywhere in the UK, just about every store stocks them. I've never seen the single use ones though

I have several of these! They're quite useful. I think I usually find them in pharmacies or camping supply stores.

Aeryn Light

You can definitely get them in brick and mortar stores in the UK - don't think they're that obscure. I've always been intrigued as to how they work, so thank you!

Kirk Northrop

Late night vid? That’s what’s up!