The Warmest Sleeping Bags and How to Avoid a Hot Mistake

Warmest Sleeping BagWhen it comes to the warmest sleeping bags here is what every camper needs to know. In this article we are going to cover how to select the warmest sleeping bags and how to avoid sleeping in the cold. We’ll discuss sleep temperatures and whether you are a cold sleeper or a hot sleeper.

In addition, you’ll learn how we lose body heat while you sleep, what makes the sleeping bag size so important, and whether to wear clothes or sleep in the buff. After reading this article you will be able to use this knowledge to avoid waking up shivering and keep warm all night long.

Cold or hot sleeper?

When you’re at home you don’t really think about whether you are a cold sleeper or a hot sleeper. If you find that you tend to kick the blankets off while sleeping in room temperature of 65°F or so, then you are probably a hot sleeper. On the other hand, if you tend to find yourself cold while sleeping in the same temperatures, then you are a cold sleeper.

Why is this important? Because the sleeping bag you choose will have a rating. These ratings mean that a sleeping bag is rated to keep you warm down to that specific temperature rating. For example, if a sleeping bag is rated at 20° then you should be able to keep warm down to that temperature.

However, if you are a cold sleeper you may need to adjust that temperature up 5° or 10° in order to be sure that you will keep warm. Someone who sleeps hot should be fine with the rating on the sleeping bag, and someone who is neither warm nor cold should adjust 5° or so.

How your body loses heat

It’s been said that we lose up to 50 percent of our body heat through our head. If you are looking for the warmest sleeping bag, then you want to be sure to find one with a hood. Most 3 and 4 season sleeping bags come with a hood.

Do we really lose a lot of body heat through our heads, whether we have a head full of hair or not? According to Dr. Daniel I. Sessler, an anesthesiologist and expert on hypothermia at the University of Louisville Medical School, that it’s a popular myth.

We do however, lose most of our body heat through sweat. If you sweat while you sleep you may need to consider why you are sweating. If you are wearing your clothes while you sleep, that may be the cause. If your clothes get wet because you’re sweating while you sleep, then you should consider wearing something else or nothing at all while you are in your sleeping bag, although that may not be the best option.

There are wicking materials specifically for sleeping in cold weather. So if you tend to be one who sweats, and we all are, you might want to consider sweat-wicking clothing.

Size matters

Let’s look at how a sleeping bag’s size can affect how you keep warm in cold weather conditions.
There are three key measurements to consider when choosing the warmest sleeping bags. They are length, shoulder girth and hip girth. Sleeping bags basically come in two sizes for men.

Regular size will typically fit someone up to 6’ tall. Sleeping bags marked long are typically for tall people and will fit someone from 6’ to 6’ 6” tall. Women’s sleeping also come in regular and long sizes usually measuring up to 5’4” for regular and 5’10” for long.

In general, you’ll want the shortest sleeping bag in order to maximize warmth. Be sure to keep some extra room in your sleeping bag so that you don’t compress the filling. Compressed filling doesn’t keep you warm. You’ll also want room to keep clothes or extra footwear inside the bag with you to keep them warm. Next let’s look at girth.

For men shoulder girth is typically 60” to 64”. However, some can be as narrow as 58” and others as wide as 66”. Women’s sleeping bags are typically narrower at the shoulders at about 56” to 50”. Girth is mostly important for comfort and warmth.

Remember, you don’t want lots of extra room in your sleeping bag because it takes more energy to heat that extra room, but you do want enough room for tossing and turning.

Sleeping BagHip girth varies for men and women. Typically, hip girth for men is 58” while hip girth for women is 60”. The best way to determine what works best for you is to try a few sleeping bags on and see which fits you best.

You may also want to consider sleeping bags with extra insulation in the feet and torso areas. If you usually get cold feet when you sleep, then this could save you when you’re out in the field. You might also consider a sleeping bag with a two-way zipper which can come in handy if you want some extra ventilation for your feet.


We’ve already touched on clothing while you sleep but let’s have a deeper look into it now. Wearing your cloths while you sleep is not recommended.

Typically, if you wear your clothing while you sleep you will sweat. Sweating is your body’s natural response to body heat or overheating. Body heat is drawn away from the body through sweating. If your clothes get wet because you are sweating, then your clothing won’t keep your body heat in and you will get cold.

So the simplest thing to consider is sleeping without clothes. Of course you may want to consider sleeping in your underwear, however, cotton material will absorb sweat, get wet and make you cold.

The best recommendation is to sleep using some sort of sweat-wicking material which draws moisture away from the body and through to the outside of the fabric where it evaporates easier.


If you’re looking for the warmest sleeping bags there are several factors to consider. Are you a cold or hot sleeper? We discussed whether you kick the blankets off while you sleep or if you sleep cold and ad more blankets.

Keep in mind that you may lose body heat through your head, so always keep your head covered. The size of your sleeping bag can actually make a difference in keeping warm. Be sure to get one that fits you properly so you will stay warm.

And finally what you wear while you sleep can make a difference on whether you sweat and make yourself colder while you sleep. Remember there’s several factors to consider when selecting the warmest sleeping bags. Choose the one that’s right for you and the conditions where you plan to use it.