Are chemical heat packs effective?

**HappyCamper** · 01-21-2008, 13:38

On another thread, chemical heat packs came up in the discussion for keeping warm.

I was wondering what experience others have had with them and whether you would depend on them as a last resort.

Here was my experience ...

My feet were very cold camping out this weekend. I could have survived the night without using heat packs but I figured why be uncomfortable since I had brought them.

I used the heat packs Sat. night at 18 degrees and they did help me. I didn't use the foot warmer packs. Those have never worked for me. Too small I think. I used one hand warmer and one larger pack that was advertised as a bag warmer. I wore one liner sock and two heavy wool socks. I opened them, shook them around and waited for the heat to start. Then I stuck them under the top wool sock down under the flat of my foot. Gave off heat all night.

In morning I put them in my pocket and they gave off heat for another 45 minutes. I believe they were 10 hour packs, but they didn't give off heat for that long. More like 8 hours.

Just Jeff reported this . . .

You should try the chem packs in a test before you depend on them as a last resort...they're not really that effective. The main problem is that they don't give off a whole lot of heat if they're not in the open air (i.e. lots of oxygen). If you stick them in your pocket, you have to take them out and shake them from time to time to keep them warm. So if they're stuck down in your bag or quilt, they won't help a lot unless you take them out and shake them...which means you have to be awake. But maybe you'll have better luck than I did...I found they were much less useful than heating a water bottle (I use soft-sided Nalgene bladders).

**pure_mahem** · 01-21-2008, 13:44

They also have expiration dates so you have to buy fresh ones if you do use them. There only good for about a year.

**warbonnetguy** · 01-21-2008, 14:39

i've opened some that didn't work at all, others that did.

**headchange4u** · 01-21-2008, 14:47

I have used them before with good results. I really like the stick on toe warmers.

If it's really cold night I will boiling/really hot water in my water bottle and put that inside a fleece stuff sack. I will then put my "heater" in the sleeping bag or under my top quilt. It will stay warm through the whole night and you don't have to carry extra weight.

**BIG-E** · 01-21-2008, 15:09

I also prefer the hot/warm beverage instead of hand warmers. If you add some sort of sugar (hot cocoa/hot koolaide), they can also supply some fuel for the furnace. I find that if I eat or drink in small amounts when I wake during cold hanging, then I go right back to sleep. It's also nice to have something in the morning b-4 you actually get up and out of the hammock.

yis,
erin

**Tobit** · 01-21-2008, 15:19

Come on, don't you wanna be hip and cool and walk around with a pair of battery powered socks on? Heh, anyone remember those things?

- JT

**Coldspring** · 01-21-2008, 18:17

Somebody give me some small reusable ones for Christmas. They are pretty neat, you just snap a piece of metal inside the pack and the liquid crystallizes and heats up. You can boil them and reuse them, but it is impractical for backpacking to use all that fuel for boiling.

**Rat** · 01-21-2008, 18:25

It just depends for me.

If I know it is going to be neeed I take the time to heat up a bottle before bed.

However the ease of chemical warmers makes them perfectly suited for 'what if' use. Like I wake up @ 5:00 AM and my feet are cold, I slip a couple of chem warmers and I'm good to go.

Speaking of battery powered socks; I have a pair I use when I fish. Sitting in an Alu, boat when it's 30 degrees on the lake catching crappie can be turture. I modified my 9v socks so I can use them with my 12v marine batteries, they are awesome to say the least! There are also full body suits made for motorcyclist, although I have never been intemperatures that needed them, there have been a few time when I sure would have liked to have had them!

**slowhike** · 01-21-2008, 19:26

i tried the chem packs a few years ago & could hardly tell if they were warm or not.
so i decided they weren't hitting on much.

but last year pan & others swore by them... so i bought more & tried them while i was working out in the cold.
they were great. as the day warmed a little, i had to take them out. my feet were over heating.

i'm thinking the 1st ones that didn't work may have been old or had developed pin holes in the pack, exposing them to air.

as long as they are working as they should, they put off a decent amount of heat in a small, enclosed environment.
but if you need serious heat, the hot water bottle is hard to beat.

**Tobit** · 01-21-2008, 20:51

Originally Posted by Hogn8r

Speaking of battery powered socks; I have a pair I use when I fish. Sitting in an Alu, boat when it's 30 degrees on the lake catching crappie can be turture.

Heh, that's not fishing!

Come up here where the ice is 3' thick and you run around the lake all day chasing the "tip-ups".

Didn't think people still used those battery socks, figured it was just one of those fads when I was a kid. Cool that they have improved and work well.

- JT