Hi George,

That’s good advice about the down booties, but I would add the caveat to start with your feet and the booties already warm before getting into the sleeping bag because it can be hard to warm up your feet when they’re cut off from the heat of the rest of your body (as they would be in booties). Thanks for sharing that perspective.

Thanks, Adil, and having a wet bag when camping anytime is miserable, but even worse in the snow, which is already cold to sleep on. I’m wondering whether moisture wet the bag from the outside, coming from the snow or condensation on the bag’s shell, or from the inside, because the bag doesn’t breathe well enough to move out the moisture your body normally releases during the night. Figuring out the cause is crucial to figuring out the solution. Thanks for sharing that story and feel free to add more details about it, I’ll respond again.

I am from the Extreme north of Pakistan. Here we have a temperature of -30 °C in winter, but we do have snow in the mountains throughout the year.

As you love trekking we also. I have a sleeping bag which is actually recommended for use in the snow (This one I recently bought). I was quite excited to test the new one and I was hoping it will give enough warm in the snow. But it was getting wet after using a few hours in the snow. Overall it was a horrible experience for me. The reason for sharing the story is I found your article quite helpful which I will definitely try next time and would love to share the feedback here again.

Thank You for the nice article

Thanks for your thoughts on this, Stuart. In my experience, after sweating a lot during the day, that dried sweat can conduct heat away from your body unless you wash. The added comfort also helps you get a good night’s sleep.

Thanks for sharing your experiences, Don. Sounds like you are a warm sleeper but I agree with not overdressing in a sleeping bag, as I’ve noted in tip no. 3 above and comments below.

Hi Rick,

Look more closely at my tip no. 3 above because I think you just agreed with my suggestion for wearing just one or two base layers and not more than that in a bag (along with more detailed tips). My coldest night was also around -30 F.

Thanks for sharing your experiences.

Thanks for sharing those suggestions, Steve. I mention the insulated air mattress above, which is important even on most summer trips in the mountains and I have spent many frigid nights outside in winter (and wrote a how-to guidebook about winter camping). I agree about the value of high-quality gear, including bags, although I have used many bags that I consider excellent and I would respectfully not agree that Wiggy’s makes hands-down the best bags out there. See this menu of all sleeping bag reviews at this blog.

Hi Mark,

Actually, that photo was shot with an ultra-wide-angle lens, which visually greatly exaggerates the length of that bag. The bag was fine for him.

Hi Matt,

Thanks for sharing those thoughts. I’m no scientist but I think your calculation about the completely true fact that water conducts heat better than air as proof that a full bladder drains precious calories/heat from your body overlooks a key fact: The bladder isn’t surrounded by air or independent of your body, it’s within your body. Plus, you could be waking up cold for reasons entirely unrelated to the fact that you have to pee (which is common if you wake up at night warm, too).

Water conducts heat 25 times better than air. It would stand to reason then, that a full bladder will suck more of your body heat than an empty one. And I have plenty of real-world experience to form my opinion. I almost always ‘go’ before bed (even at home) but on the occasions that I wake up in the backcountry at night, I virtually always find myself cold AND having to pee. The internal debate always rages about being able to hold it until morning, but invariably I always end up thanking myself by falling right back asleep, warm and comfortable, after making the right decision.

Hi Wayne,

That advice can be generally true because wearing just some base layers helps the warmth created by your body’s core (its furnace) allows that heat to fill the entire bag, warming your extremities, rather than trapping all that core heat inside, for instance, a puffy jacket when in your bag. It’s also just naturally more comfortable to not wear a lot of layers when sleeping. I usually wear socks (my feet get cold easily), a short-sleeve or long-sleeve top, and underwear, plus a hat when needed. But if your bag isn’t warm enough and your body’s core gets cold, your only option for warmth is to add layers. Thanks for the comment.

Hi Jeff,

I personally don’t get cold too easily—which makes a difference—and I’ve always used a 30-degree bag through September in the Sierra, sometimes even into October. I’m going this August and will definitely use a 30. I agree that it’s easy enough to supplement with clothing layers if needed, but I’ve never needed more than a hat, socks, and one base layer top and bottom, rarely even all of those. Bring an air mattress with an R-value of 2.5 to over 3 for three-season temperatures.

Thanks for saying so, Phyllis, and good luck.

Thanks for sharing that, Michael. I have not tried a heated vest but I imagine some other people might have the same good results as you get with it.

Hi Anthony,

Sorry to hear about your accident, that’s horrible. Thanks for sharing it to alert other readers. Yes, you do have to use a sturdy plastic bottle that’s designed to hold hot liquids, like a Nalgene bottle. Good luck with your recovery.

Thank you, Kayla.

And thank you for the affirming comment!

Hi Hadi,

The tips in this article are applicable to any temps, even well below freezing. (As I noted at the top of the story, my coldest night outdoors was -30 F.)

Your question spotlights a real challenge for people heading out in very cold temperatures: How to keep your gear kit manageably light and stay warm and protected from the elements?

There is excellent, relatively lightweight gear out there for extreme temps, including in the categories that will comprise the bulk of your pack’s weight: shelter, sleeping bag, pad, and clothing. I’ll point you to a few examples I’ve reviewed recently: the Mountain Hardwear Phantom 0 bag (2.5 lbs.), the Sea to Summit Ether Light XT Extreme insulated air mattress (1.5 lbs.), the four-season Hyperlite Mountain Gear Ultamid 2 pyramid tent (1 lb. 2 oz.), and my picks for the best clothing layers for winter.

The hard reality is that high-quality, lightweight gear like that is expensive.

You could also forego the tent and build yourself a quinzee snow shelter, which I’ve done many times in different areas, including New England, where the snowpack is probably similar to Minnesota’s. You can find instructions for doing that right online.

See this menu of all gear reviews at The Big Outside and my “10 Tips for Spending Less on Backpacking and Hiking Gear,” and “12 Pro Tips for Staying Warm Outdoors in Winter.”

I hope that’s helpful. Good luck and stay safe and warm.

I like most of your tips and actually for first time borderline freezing temp novices – this advice couldn’t be better! Safe, simple smart and no shi shhhh bologna.

However, I’ve slept in sub-freezing temperatures backpacking in a field (baddddd choice with my summer tent) and survived backpacking where not many people usually wander. Most are climbers doing the cold weather thing. Well either I’ve grown entirely impatient, bored out of my mind or I’ve gone completely mad because I’ve decided I can’t wait anymore for spring and during our Minnesota snowstorms I’m going to try what I call board backpacking (snowboarding and backpacking) which means hiking to the top of a remote location with snowboarding gear with the intent of hunkering down for the storm and when it’s done… Boards on, I’m out ripping down the fresh powder. Completely and utterly alone (besides my dog).

The climates breaking down we have -30 windchill and that’s as good as it’s going to get. I have to deal with it or stay home.

My question to you is: gear. How does one 135 lb girl and her not-snow dog stuff that much gear into a sled/backpack for 7 days and keep it light, keep it warm, keep it real?

I heard Tyvek makes for great insulation outer bivy layer?

Right on, Matthew.

That’s a good suggestion, Brian. Thanks.

Thanks, Steve. In fact, I just followed many of these tips for three nights outside in late December in the central Idaho mountains and slept warm and comfortable.

You’re welcome, Melissa, and have fun with your son!

I think that’s called a tent, right?

Thanks, Lee, provide us with more details about that, if you can, to help us understand what you’re describing.

Hi Karen,

Thanks for your kind words about my blog, I’m delighted you find it helpful in many ways, specifically this story and my tips on getting a last-minute Yosemite wilderness permit and my story “The First 5 Things I Do in Camp When Backpacking.”

Thanks also for your good question. The first piece of advice I’d offer is that you probably just need a warmer bag for the temps you encountered in Yosemite—with a forecast for lows in the upper 20s at 8,600 feet in Tuolumne Meadows, you certainly would have pushed the comfort range of your REI Joule 23 at 10,000 feet, even if you don’t get cold easily. The Joule 23 is a decent bag, but I suspect many people would find it inadequate for temps lower than the upper 20s Fahrenheit.

The Feathered Friends Egret 20, on the other hand, is among the very warmest bags in that temp rating range, speaking from my experience with the men’s version, the Hummingbird 30, which has kept me warm in temps at and just below its rating. Besides having the highest-quality down available (950-fill), FF packs those bags with more down than you’d find in many similarly rated competitors. Lay the Egret 20 beside the Joule 23 and you’d see a visible difference, I think. I suppose FF calls it a “passive collar” because it’s not a flap like a draft collar, but nonetheless, the bag closes up snugly around your neck and face to trap heat. The Egret also has extra down in the foot box. Continuous baffles can allow down to shift a bit, but I’ve never experienced cold spots in my Hummingbird, perhaps just because it’s stuffed so fully, and I’m also a side sleeper.

The Egret medium also has a length of five feet, nine inches, just about perfect for you. A bit of extra length is good, allowing you to pack extra clothes under your feet and at the end of your bag. But if it’s too much longer than your body, the foot box will become a cold spot that you’ll notice when fully extending your legs. Greater bag volume overall also means your body has to warm a larger space, which can compromise your warmth.

You followed many good practices for keeping your feet warm—short of putting a tightly sealed bottle filled with hot water inside your bag (or two, one near your stomach and one at your feet)—which also leads me to believe your bag simply wasn’t warm enough.

Pulling on a down jacket (or other non-breathable insulation layer) inside your bag will boost heat to your torso, but also trap it around your torso; and because your core is your body’s heat producer, the down jacket blocks that heat from circulating throughout your bag to help warm your extremities. It’s less of a problem for hands, which are close to your torso, than feet, which are farther away. Once your feet get cold, it’s hard to reward them, especially because your brain will cut off blood circulation to cold extremities to protect the vital organs (called vaso-constriction).

That’s why I’ve always found it more effective to wear just breathable layers inside a bag, including a warm hat and socks. I’ve spread a down jacket out over my body inside a bag and felt it deliver a fast boost of warmth that spreads throughout my bag, including to my legs and feet. Down booties may help warm your feet and will be more effective if you pull them on while your feet are warm; if they’re already cold when you put them on and then immediately crawl inside your bag, you might isolate your cold feet from your body and delay their warming.

I hope that helps. Thanks again for the good questions and get in touch anytime.

We spent several nights near or just over 10,000’, and I was cold in the early morning hours. Not sure what the exact temperature was, but when we departed the forecast for Tuolumne Meadows (8,600’) was lows in the upper 20s.

I’m now evaluating whether there are steps I can take to ensure my comfort on late summer/high elevation trips or if it’s time to update my 2014 REI Joule 23. I just read over your post with tips for staying warm in a sleeping bag (I did many but not all the tips) as well as your 2021 review of sleeping bags and have a couple of general questions as well as more specific questions about one of the recommended sleeping bags.

1. In terms of “dressing smartly,” you mention wearing a breathable baselayer to allow core heat to disperse. As I got chilly, I pulled on my Nano Puff jacket and hood rather than draping it over my torso. Was that the wrong approach?

2. My feet were cold despite wearing clean wool hiking socks. I had a seat pad under my feet and extra clothes inside my bag under my feet. Do you think wearing down booties is an effective approach?

3. I’ve read that a sleeping bag with a draft collar will be warmer than one without it. My current bag does not have one. In considering the Feathered Friends Egret UL 20 that you recommend, I notice it lacks a draft collar and instead has a “passive collar with an extra cushion of down.” From your experience, does the design of the Egret essentially work like a draft collar?

3. The Egret comes with continuous baffles. Is there a downside to this design? Are cold spots more likely if the down has not been evenly distributed? Might a side sleeper who switches from side to side during the night shift the down and create cold spots?

4. How does the length of the sleeping bag affect warmth? I ask because my height is 5’ 6½” and many women’s bags use 5’ 6” as the break between a small and regular sized bag (or regular and long). I do tend to have cold feet in general. Is it best to go for slightly long or short?

I have found valuable information in many of your posts and appreciate any guidance you may be able to provide me. I understand if you think my specific questions about the Egret UL 20 should be answered by Feathered Friends.

Thanks for your tips and inspiring work,
Karen

Solid advice, Nick. Thanks.

Thanks for the good suggestion, Rak. In my experience, people often make mistakes in the backcountry not because they’re stupid but because they’re inexperienced or uninformed in some skill or environment, and sharing information is, hopefully, the way to avoid bad outcomes.

Thanks for the suggestion, Sally.

Thanks, Edward, I’m honestly not familiar with any research or data behind sugar, Alzheimer’s, and dementia. I’m simply suggesting that consuming fat before bed when camping in sub-freezing temps has always given me a long-lasting boost in warmth, much as consuming fat boosts warmth and energy when I’m active during the day in sub-freezing temps.

Tip #9, eating before going to bed… while the rare occurrence likely will have no observable effect, please Google and reference articles discussing the effect of sugar and digestion time lapse upon the brain as relates to Alzheimer’s and dementia.

As always, thank you for your articles and insights, helps me get through the day while waiting for the next opportunity to visit The mountains.

All good tips, John. Thanks for sharing them.

Great tips. A few that work for me. I carry wet ones for clean up, especially when it is cool/cold or at elevation. I carry down booties for those same conditions. They are light but great warmth.

When buying a bag make sure it is not too tight fitting because it is more difficult to use a liner or add layers. Or too large as there is too much space to warm.

Head wear can vary from light, medium or heavy. Same with liners.

For cold trips take a pee bottle. Make sure it is marked or an unique shape. Close it tight.

If you can, shift your down (if you have a down bag) to the top and sides. When you lay on the down it compresses loosing most of its insulation value. Better yo use that second pad, clothing, your empty pack, etc that you recommend underneath.

Avoid or minimize the amount of condensation. Similarly avoid/minimize perspiring. Moist down does not insulate as well. Also, dry your bag whenever you can. Even in cool/cold weather keep your tent ventilated.

Cheers

Thanks, Jes. I first heard that tip years ago. I’ve debated it with friends who have science backgrounds and insist that the body would not burn any more energy heating urine that’s inside the body that’s at body temperature, anyway. My take is that staying well hydrated certainly helps keep you warm, and I relieve myself right before bed in hopes of not having to get up during the night; but if I have to, I do get up, because it’s hard to sleep otherwise. Keep a warm puffy jacket handy to slip on if you have to get up.

My pseudo-science theory as to why this seems to work: instead of your body working hard to keep all that pee at a toasty 98 degrees, it can use that energy to keep the rest of your bits warm.

Take it or leave it . But I’ve decided a few seconds of cold booty is worth hours of greater warmth in my bag.

For colder weather I have two more sleeping bags. One is a 3-season sleeping bag, another one is a 4-season sleeping bag.

There is definitely no need to spend 300 or 500 USD for a summer sleeping bag. Don’t get fooled by the “amazing features”. A warm weather sleeping bag can be as simple as it can be…