Using A Hot Water Bottle To Stay Warm

**Gadget** · 01-16-2012, 12:39

Ive used this trick many times to stay warm, its still hard to beleive that the bottle is still warm in the morning but it is. Gives you a headstart on coffee and grits too.

**scum** · 01-22-2012, 01:31

So, I made a very nice reflectix cozy for my nalgene. Does a great job of sealing it up completely to help retain the heat as much as possible.

I've done two tests so far:
1st test, I left the bottle sitting out of my bedding besides me (indoors). When I got up at 3am, reflectix was cold and bottle was luke warm at best - not warm enough to be a viable source of heat.
2nd test, I slept with it in the bedding with me. Woke up at 5am. The cozy was luke warm so I pulled the bottle out and the bottle was still warm enough to supply maybe another 1/2 hour of mild warmth. Probably not enough to really help in the deep cold though.

So the 'well, duh' conclusion for me is that the bedding really makes a big impact on how long your bottle will last. If you're using the bottle to supplement poor insulation in the deep cold - it won't last much longer than a few hours. If you've got adequate insulation, then chances are better it will last you through most of the night.

I will be camping in (hopefully) some good winter conditions this weekend and will be putting this to the test again. I'm really hoping that being sealed up with me in my TQ/UQ will boost things even more than just laying with me in my loose bedding at home. If all goes well, I'll finally find that elusive warm bottle in the morning everyone keeps talking about...

-scum

**Weasel** · 01-22-2012, 01:59

The one and only time i did this was by accident bc i brewed tea before bed and didn't drink it all. I put in tea that was roughly 180* into a nalgene cantene and put it between my legs as everyone else said. I slept too warm that night, i had to pull off my sleeping bag. I didn't use a bag or anything, just tightened the lid as tight as possible. I don't shift too much unless i have a pad inside my hammock with me, so i felt a little safe.

**rip waverly** · 01-22-2012, 03:28

i boiled water before hitting the hammock at the frog lake oregon hang the second night. the bottle was a camelback type. i used nothing to insulate the bottle itself - ie - no wool sock, reflectix cozy, etc.

temps dipped to 19*F, and the bottle was nestled somewhere against my body, in my top bag. when i awoke to the sun & snow, the bottle was warm. i guess i'd call it similar to water that has been poured into a glass and left to sit on the kitchen counter all day - or - room temperature.

not bad. makes a mid-night swig easier to gulp than ice cold water and expedites morning coffee boiling.

**Miguel** · 01-22-2012, 08:33

Originally Posted by Bphil

I wonder if this could be done with a Platypus bottle. They are much lighter and would probably be more comfortable to sleep with. Anybody ever tried?

My Geigerrig bag (which is basically the same) is dishwasher safe. I'm not sure what the temp is in the dishwasher but it's hot enough where I can't touch the dishes if I open it right away. I may check Geigerrig's site or email them on the subject.

I'm leaving on an AT hike in the spring with a 30 degree bag so this subject has crossed my mind.

Miguel

**Porloff94** · 01-23-2012, 12:06

Used this trick on the Klondike Derby over the weekend. Temp dropped to 18 degrees. My son (in his tent and 20 degree bag) woke up in the morning with nary a complaint of chills. It supplemented nicely and kept me warm in my WL TQ and 3/4 UQ. Still warm for a morning coffee starter.

MT · 01-23-2012, 12:58

I used this trick at the Frozen Butt Hang this weekend. Worked very well at -20 and -15*. I had a nalgene bottle between my legs to begin with, but moved it after a while, because I got too hot. Wound up wrapping it in a sweater to keep it warm for the morning coffee starter.

**LazyBee** · 01-30-2012, 21:44

I just spent two nights in the north Georgia mountains with a bunch of friends and a couple of them decided to give the "almost boiling" water in a Nalgene quart bottle a try since it was really cold this past weekend. They claimed it was the best thing ever to keep a warm spot going as it dropped to the mid to low 20's Saturday night. The PROBLEM was when they went to unscrew the top it was "fused " on the next morning!! The remedy= boil a couple of cups of water and carefully pour slowly around the top and threads and it will then unscrew easily. This was repeated on two bottles with ease.

It works!

**scum** · 01-30-2012, 23:24

Well, I had intended to use the bottle for my last campout, but the temps were so cold that my normal gas canister stove failed miserably and even my backup alcohol stove could barely keep a flame going. Had to resort to my backup handwarmers. Grrrr...

Should have brought my wood gas stove as backup instead of the alcohol stove I guess. I'll have another go at it on next months campout...

**jeepcachr** · 01-31-2012, 13:11

Originally Posted by LazyBee

I just spent two nights in the north Georgia mountains with a bunch of friends and a couple of them decided to give the "almost boiling" water in a Nalgene quart bottle a try since it was really cold this past weekend. They claimed it was the best thing ever to keep a warm spot going as it dropped to the mid to low 20's Saturday night. The PROBLEM was when they went to unscrew the top it was "fused " on the next morning!! The remedy= boil a couple of cups of water and carefully pour slowly around the top and threads and it will then unscrew easily. This was repeated on two bottles with ease.

It works!

I've never had one that was difficult to open in the morning. Were these Nalgene brand bottles? Big cap or small cap? Mine are all big cap.