sleeping bag sweat management issues

Hello,
I have an issue with all the sleeping bags (mummy bags) I've tried.

I get an excessive build up of sweat between my legs in the groin area that makes sleep very uncomfortable, if not impossible. Since I'm a side sleeper and my legs are confined in a mummy bag, my legs are constantly on top of each other and this sweat never dries.

I often find myself stuffing a sweater between my knees to create some extra breathing room, but this rarely helps much.

This is something that happens in all temperatures I've slept in (25F-65F)

About me
Male, 6', 195 lbs
I've tried various sleeping bags, but my current is a sierra designs dridown zissou 23.
I've tried various boxers/boxer briefs, including smartwool microweight boxer briefs, exofficio boxer briefs, adidas boxer briefs, REI syn boxers, and regular haynes boxers.

So, is this something that can be avoided somehow? If so, what can I try to make this better? This is, by far, my biggest nuisance when sleeping outdoors.

Thanks!

Try leaving the bag unzipped so it vents a bit, or switch to a quilt!

If venting doesn't help, they make small sample size baby powder/talcum powder shaker bottles. DON'T get any of the medicated ones like Gold Bond!!!!!!! Helps with any chafing issues and feels good on your feet, too. I've had the same problem, but on the trail, the powder did the trick.

Yea, when it's warm enough to sleep with the bag open, I sleep great. Otherwise, unless the weather is in the 60s, I get too cold.

I normally sleep in just boxers as I'm more comfortable that way (I toss and turn a lot)

Have you tried sleeping in the bag quilt style - i.e. zip up the footbox to put your feet in, open the bag out flat and sleep underneath it - no bag underneath you just your sleeping pad.

I'm a big sweaty guy and I have the same problem - it's usually much better when I do the above, which is probably 95% of the time I'm in a sleeping bag.

The other thing I find *really* helps me is to bathe that area at the end of the day - even if it's just water - which it usually is for me. I take a dip, or even a little "sitz bath" type washoff using a pot or two of water - YMMV.

I've never tried the powder..

I laughed then I cried then I threw up a little.

Well, I do specialize in adding bad scenery to otherwise amazing places - especially when bathing..

Thanks guys. Will try some baby powder and sleeping with the bag open quilt style. Going on a 30+ mile weekend trip tomorrow am. Forecast looks to be 40F at night with some rain. Will let everyone know how it goes.

Ok, got back from my trip.

Before bed, I applied baby powder to the "problem area" and unzipped my sleeping bag completely, and wore it like a blanket. I slept great until around 3 or 4am, when I got cold.

Now faced with being cold, I zipped up my sleeping bag, and attempted to sleep. After sleeping briefly, I woke up to find my boxers literally soaked with sweat. I applied more baby powder, which helped me fall back asleep, but I'd wake up soon after with the same problem.

In the morning, I noticed even my arms and shoulders were sweaty

Any more tips? Thanks!

Henry, I'm up in the wee hrs. to catch a plane to the Grand Canyon for a bucket list backpack, so all I can say is I'm glad we helped a little. I read some stuff on line- just research "night sweats" and "sweating in the groin" and a number of good explanations come up. I was surprised that cotton briefs are called for, rather than any type of boxers. I've got one more suggestion- keep your head warm with a hat so you don't need the warmth of the bag quite as much if you aren't doing that already. My best wishes for a solution!

First and foremost I would say you should talk to a doctor. The inability of your body to thermoregulate could be a sign of a medical condition.

If that checks out, you could try things in between fully zipped and blanket mode: just zip the foot box up... too cold? zip up further or put on a hat... too hot? stick a leg or an arm out.

Hmm, I don't have any sweat problems sleeping anywhere else. Heck, even car camping with a rectangular sleeping bag works fine for me.

I wonder if it's because I sleep in just my boxers. I'll try wearing a base layer and a hat next time. Maybe with a base layer I'll be able to leave the bag unzipped down to lower temps.

Thanks!

I had a similar problem where I would be cold before I fell asleep so I bundled up and was warm and fell asleep easy, then I would wake up sometimes sweating because I had added too much insulation to warm up so I could fall asleep again. I would definitely try sleeping in a base layer or something similar so that you have a little more insulation directly around your body. That way your core temperature will stay a little more constant and be less effected by changes in the weather (wind, temps, etc.)

Also do you use a tent, tarp, bivy, or what when your backpacking? If your in a tent the microclimate should be a little more consistent than if you're using a tarp or sleeping under the stars.