Crawling into a sleeping bag after a long hike is one of the simple joys of camping, but what do you wear in your sleeping bag? I can’t count how many times I’ve heard that sleeping naked in a sleeping bag will make you warmer. Should you ditch your pajamas and crawl into your sleeping bag naked the next time you go camping? Or is that just another myth that people can’t seem to let go?
Should You Sleep Naked in a Sleeping Bag? There’s rarely a good time to sleep naked in a sleeping bag. Wearing clothing in your sleeping bag will keep you warmer, protect the bag from sweat, dirt and body oils, and leave you ready to hop out of the bag at a moments notice. Stripping down to your underwear might work in the summer, but it’s almost always warmer to wear comfortable pajamas, long johns, or sweatpants to bed on cold nights.
I’m not telling you that stripping down before crawling into your sleeping bag is a terrible idea. I wouldn’t recommend it, but there are loads of experienced campers that choose to sleep in the nude or strip down to their underwear on camping trips. There are plenty of situations where that makes sense, but just as many times where it doesn’t.
Sleeping naked will make you colder, expose the sleeping bag to sweat, dirt, body oils, prematurely wears your sleeping bag, and it puts you in a compromised situation with only a thin fabric wall between you and the outdoors. Packing in sleeping clothes adds a little bit of weight to your pack, but it’s almost always better to wear clothes to bed.
If you do decide to strip down, I highly recommend purchasing a sleeping bag liner. It will make you warmer at night and keep your sleeping bag clean. Sea to summit makes the best sleeping bag liners and they come in a variety of temperature ratings.
I use the Reactor Extreme liner which adds 25°F of warmth to your bags temperature rating and it’s warm enough to be used by itself on cool summer nights. Even a cheap Coleman Liner will add 15°F to your bags temperature rating and it’s temperature rating is like a 50°F sleeping bag. Adding a liner to your bag will reduce wash cycles and extend the life of your sleeping bag.
In the rest of this post I’ll go over why you shouldn’t sleep naked in your sleeping bag and go over a few exceptions to the rule. By the end of this post you should be able to decide whether or not you want to wear clothes to bed on your next camping trip.
Sleeping Naked in a Sleeping Bag
I don’t know where the concept of stripping naked before crawling into your sleeping bag came from. It’s an old wives tale that won’t go away. Stripping down to the nude won’t kill you, but it’s almost always a better idea to wear something to bed while camping. Here are the main reasons why you shouldn’t sleep naked in your sleeping bag.
- Sleeping Naked Will Make You Cold: There are a few exceptions to this rule, but it’s almost always warmer to wear clothes to bed. Every layer of clothing you wear to bed will increase the amount of insulation between your body and the cold outside air. This isn’t a huge deal in the summer, but it can really bump up your sleeping bags temperature rating on cold nights.
- Makes Your Bag Dirty: I’m usually covered in dirt, sweat, blood, and who knows what else by the end of a long day of camping. Do you really want to get all that grime on your sleeping bag? Wearing clothes to bed is an easy way to protect your sleeping bag so you don’t have to wash it after every trip. I also use a Sea to Summit Reactor extreme liner to further protect my bag. It adds 25°F of warmth to my bag on cold nights and can be used on its own on chilly 50°F nights.
- More Wash Cycles: You should really try to avoid washing your sleeping bag if you don’t have to. Every time you wash your sleeping bag the insulation compacts making it less effective and you run the risk of tearing the bag. Wearing clothes to bed reduces the amount of sweat, dirt, and body oils that get onto your bag. When you pair it with a sleeping bag liner you shouldn’t have to wash your bag more than once per season (maybe less).
- Not Ready For Action: You never know when you’ll have to get up in the middle of the night. Maybe you have to pee, you hear a loud noise nearby, or animals are going after your food stash and you need to chase them off. Needing to put your clothes back on slows you down and prevents you from getting back to sleep.
Those are the main reasons why I choose to wear clothes in my sleeping bag, but there are times when I’ll strip down. Most of the time I wear pajamas, sweatpants, or gym shorts to bed, but I’ve been know to strip down to my boxers on hot summer nights. It all depends on the outside temperatures and I use a sleeping bag liner so I don’t have to worry about getting my bag sweaty.
Before I get into that let’s go over how a sleeping bag keeps you warm. That should hopefully clear up a few things and explain why it’s better to wear clothes to bed.
How Sleeping Bags Keep You Warm and Why It’s Better To Wear Clothes To Bed
Sleeping bags are designed to trap your body heat preventing it from escaping. It’s almost like the insulation in the walls of your house. Adding more insulation to the exterior walls of your house will increase the efficiency of your furnace trapping in heat.
When you crawl into a sleeping bag your body acts like a furnace heating up the inside of the bag. Your body’s metabolism burns stored fat, glycogen, etc. and releases body heat to warm up the bag. Heat transfers from hot to cold areas. So if the outside temperatures are colder than the bag you’ll slowly lose heat through the bags insulation.
Hopefully you chose a sleeping bag with a temperature rating 15°F colder than expected nighttime temps so your body can produce enough heat to maintain the temperature in the bag. Wearing additional layers to bed and using a sleeping bag liner will add insulation to the bag and help the temperature rating.
Stripping down won’t be a big deal if your sleeping bag is within the recommend temperature range, but you’ll quickly lose body heat if you underestimate the nighttime temperatures. That’s why I always wear a pair of long johns, sweatpants or pajamas on chilly nights.
It’s so much easier to unzip the sleeping bag to let in cool air than get out of your bag and throw on warmer clothes. At the very least you’ll want to wear socks to bed. I hate sleeping in socks, but your feet are always the coldest part of a sleeping bag. Your body releases most of its heat through your torso and legs so the bottom of the bag will get cold before the rest of the bag.
Sleeping Naked Will Ruin Your Bag
Backpackers really shouldn’t wash their sleeping bags between every trip. Washing between every trip will significantly reduce the lifespan of your sleeping bag (especially with down filling). Washing machines tear through sleeping bags and insulation will compact with every wash cycle hurting the temperature rating.
Sleeping naked will increase the amount of grime that gets on your bag. The average person releases 2 liters of sweat per night in their sleep. It’s like dumping a 2 liter bottle of sweat in your sleeping bag every night! That sounds pretty terrible to me.
You also have to factor body oils, salt, and all the dirt you picked up on the trail. An entire days worth of filth will get into your bag without access to a shower. Wearing clothes to bed will add a layer between your dirty body and the inside of your bag.
If you can’t wash the bag how can you keep it from getting nasty? Wearing clothes to bed will help, but if you insist on sleeping naked you should take another step to protect your bag. I highly recommend using a sleeping bag liner to protect the inside of your bag. They absorb all the sweat and dirt so you won’t have to wash your bag between trips.
Sleeping bag liners are more durable so they’ll hold up in the washing machine and there’s no insulation layer so you don’t have to worry about damaging the temperature rating. Just toss the liner in your washing machine on Hot and wash it like any other blanket.
I’ve always used the Sea To Summit Reactor Extreme liner, but it can be pricey. It adds 25°F to your bags temperature rating and it’s heavy enough to be used instead of a sleeping bag down to about 50°F nights. If you can’t fit a Sea To Summit liner into your gear budget Coleman’s Sleeping Bag Liner is a much cheaper alternative. It’s on the heavy side at 1lb 10oz, but it’s cheap and adds 12°F to your bags temperature rating.
There Are A Few Exceptions To This Rule!
With everything in life there will always be exceptions to every rule. It’s rare, but there are times when wearing clothing in your sleeping bag will make you colder. Here are a few examples of situations where you might want to shed the extra layers of clothes.
- Wearing Too Much Clothing: Sleeping bag use their fluffy insulation to trap body heat, but wearing lots of clothes can sometimes hamper that insulation layer. Wearing a light base layer to bed won’t cause major problems, but throwing on lots of layers and jamming your bag with gear can impact the temperature rating. This is only an issue if there’s so much stuff in the bag that it compresses the insulation layer in the bags baffles.
- Cutting Off Circulation: Tight socks and long underwear might cut off circulation in your body. With less blood going to your arms/legs your body is going to feel colder.
- Special Medical Conditions: Some medical conditions like diabetes and high blood pressure cause circulation problems. Extra layers are going to further exasperate the problem.
- Moisture Buildup: Never get into a sleeping bag fresh out of the shower or with wet clothing. Moisture on your body soaks into your bag and reduces insulation.
- Excess Sweating: You’re the only one that knows how much you sweat at night. Personally, I can’t sleep in a shirt because I sweat like crazy. I actually use a sleeping bag liner to protect my bag while increasing warmth.(my budget sleeping bag liner)
Staying Warm in a Sleeping Bag
Staying warm in a sleeping bag really isn’t all that difficult. Just remember that not all sleeping bags are going to have the same R-Value. You don’t want to use the same bag in the spring/fall as you do in the summer. (my favorite cold weather bag)
The Best Way to Sleep!
- Wear a dry base layer to keep your sleeping bag to keep you warm and keep your bag clean. Choose a loose fitting outfit that will keep you warm without cutting off circulation.
- Use a sleeping bag liner to both protect your bag and add another layer of insulation. Bag liners are easier to wash and will significantly increase the temperature of your bag. When the weather is warm you can even ditch your bag completely and use the bag liner instead. (here’s a budget bag liner that adds 12 degrees to your bag)
- Buy a bag with enough room to move around. Bigger guys aren’t going to be comfortable in a small sleeping bag. Get a bag designed for larger guys if you’re 6ft or taller.
- Never sleep in wet clothing. If your base layer is wet you’re better off ditching your clothes and putting on a dry outfit. Without access to dry clothes you’re better off sleeping in the nude.
- Use your zipper to regulate the temperature in your bag. If you start to sweat unzip your bag and zip it back up as you get cold. Your body heat changes throughout the night so you might need to zip back up in a few hours.
Other Gear That Will Keep You Warm
- Sleeping Bag Liner: Sleeping bag liners will turn a cool summer bag into a cool weather bag. Cheap liners (like this one) will add 12 degrees to your bag, while warmer liners (like this one) adds up to 25 degrees to your bag.
- Sleeping Pads: Sleeping pads don’t just add padding to the ground, they also lift you off the cold hard ground. They add an additional insulation layer between you and the ground. (My favorite Pad)
- Cold Weather Bags: Not all sleeping bags have the same R-Value. You need to buy a bag that’s specifically designed for winter use.
- Eating Before Bed: Eating before bed will slightly increase your body heat.
- Winter Hats: In most sleeping bags your head is going to be exposed to the cold air. Throw on a winter hat on those especially cold nights.
