@TEDthebed  Well you won't know if a hot water bottle works for you unless you try.  You can just use the bottle to initially warm the bag and take it out when you get in.  Or eject it later if you feel it is not doing much.  You can try it at home to get comfortable with it.

It is also easy to try a blanket over the top of your sleeping bag. For car camping you can just take one or two from home and see what it takes.


@TEDthebed what exactly was your 'sleeping pad', please describe it, thanks!

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Hey @TEDthebed 

This is a great question, and I think a lot of people have issues with sleeping cold. The first thing to understand is that while sleeping bag temperature ratings have come far in terms of accuracy, everyone has a different metabolism and can run hotter or colder than the test that derived the temperature rating for your bag. 

We also use a "recipe" to get as close to the published temperature rating as possible - which it sounds like you are pretty close to following. Midweight base layers, an insulated pad, socks and a hat. 

The portion of the formula that we don't have info for is your sleeping pad, so as someone else mentioned, make sure your pad has a high enough R value to keep you insulated in cold weather. 

You could add a liner to increase your warmth, but you shouldn't add much in the way of more clothing - as you slow the rate that you are actually warming the sleeping bag. 

Also, make sure the sleeping bag isn't too long for you. Cold feet are common if you are in a bag that is much longer than you are. If that is the case, you can stuff some extra clothes below your feet, or even put the sleeping bag stuff sack around the bottom of the bag to close off the extra space. 

Finally, try stoking the metabolism fire! A hot beverage (Hot chocolate is great!) to both warm you internally, and supply sugar to your system to burn for heat. 

Exercise (but don't sweat!) can also help you warm up right before bed, then it is easier to warm your bag. 

You can also try a heat source inside your bag - Try putting hot water in nalgene bottle (make sure the cap is on tight!) in your bag to pre-warm your bag. Just wrap it in something (a wool sock) so it doesn't burn you. 

For extra points, put Jello in the water bottle with hot water, when the bottle is no longer hot, take it out of your bag. The cool air will chill it, and in the morning.... JELLO! There is always room for Jello and the sugar will stoke your internal fires again, helping you get your day started!

Good luck!

At REI, we believe time outside is fundamental to a life well lived.

Hi @TEDthebed - sorry you had cold legs and feet. I am a very cold-natured person, so I feel your pain! 

@REI-BrettF gave some great suggestions, especially the warm water bottle trick which is one of my personal favorites!

Other things I would recommend would be to empty your bladder before you get in your bag. Your body works so hard to keep your urine warm, that it can compromise the heat that goes to your extremities. That also means getting up in the middle of the night if you need to pee!

I have recently converted to Down Booties and have noticed a significant difference with how much warmer my feet are while camping! I think my midweight merino wool socks were too snug around my calves (which are honestly not that impressive), and were therefore reducing blood flow - and therefore warmth - to my toes. Down booties are light and packable, so they are easy to backpack with! And happy feet = sleeping well = healthy mind and body.

Hope that helps! If any of these suggestions work for you, please let us know!

At REI, we believe time outside is fundamental to a life well lived.


I ordered a “puffy” camping blanket to go over my sleeping bag. My reasoning is that I would be able to “adjust” the amount of warmth that I needed during the night. I will update with my experience.

Hot Water Bottle Thoughts

As I said earlier, I had an actual rubber Hot Water Bottle with me with the intention of heating water on the camp stove before going to bed. Bed time was around sunset as most here can relate to and the temps were in the mid 40's. A hot water bottle at that time would have made sleeping probably too warm. So, I decided that I'd forego the idea until later if I needed it. Later when I needed it, it was around midnight and I did not have the motivation at the time to get up and heat water … lol.

My other thoughts on this approach were that the water would have cooled down in a couple of hours anyway and I'd be right back where I started. The cooled water may also even act as a “heat sink” draining heat away from me as one side of the bottle would be touching/compressing the underside of the bag with very little insulation because of the compression.

I'd liked to hear others experiences on this approach. Maybe I'm missing something. Maybe the heat from the water stays around longer than I think.

Booties are my next option to try.



Cheapest two ways to add warmth:  1) Bring a warm blanket (or two) from home, and put it over (and under) your sleeping bag; 2)  Buy some of those cheap "hot hands" that last for 8-10 hours and open a couple of them up, throw them in the bottom of your sleeping bag.


Maybe the problem is not insulation but inner warmth and circulation. Insulation will not help you if there is no inner warmth to insulate. Try putting boiling water in a Nalgene bottle, making sure it is sealed tightly, and then put an old sock around it so that you will not burn yourself. But it in the foot of your bag a few minutes before turning in.  Also, make sure you ate something before turning in to fuel you through the night.

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Remember that it is easier to retain your body heat than to lose it and try to get it back.  After hiking and setting up camp and you are done sweating change into your warm, dry sleeping clothes and PUT ON A HAT while you are around camp.  Put on enough warm clothes to be comfortable but not sweating again.  Eat a lot of fats for your supper, they will digest slowly and warm you at 3 in the morning.  Once you have the correct gear then it is a matter of regulating your food intake and paying attention to warmth retention. 

During the night squeeze your toes or fingers to create circulation.  The chemical hand warmers are great for an unexpected dip but you should rely on you basic equipment (bag and pad) for the majority of your trips. 

And remember anything draped over your puffy sleeping bag will have the effect of lowering the effectiveness of that insulation (unless it is a lighter puffy thing like maybe a down jacket).  Lots of experience talking here from a chronically cold person.

I camped this past weekend in mid 30 degrees (old 1986 4-season tent).  I do have a decent insulated pad and 15 degree bag, but I find the best way I keep warm is to wear as little as possible inside my bag.  I slept very warm in a pair of shorts and a tank top.  I had to keep unzipping the bag on the second night because I was overheating.  I camped in January in lower temps and felt a little cold, but I slept in wool leggings and a wool long sleeved top.  I was cold when I went to bed so I ignored my own advice.  😄  I do still wear socks, but put on dry socks at bedtime.