How to Choose an Extreme Cold Weather Sleeping Bag

Sleeping bags are primarily meant to keep the user warm especially during the night when outdoor temperatures can get very low.

When not properly controlled low temperatures can make it difficult for one to sleep comfortably at night and ruin your camping experience. 

Beyond comfort, cold conditions can pose a health risk as the temperature is one of the major determinants of health.

Extreme low temperatures can negatively impact one’s health; in severe cases, it can cause frostbite and hypothermia. In the case, of frostbite, cold can cause severe damage to the body cells while hypothermia is a medical emergency in which the body temperature gets abnormally low due to prolonged exposure to extreme cold. The body can get lower than 95 F in these conditions.

Related Post: Everything You Need to Know: How to Choose the Best Air Mattress for Camping

Hyke & Byke Quandary 15 F Hiking & Backpacking Sleeping Bag - 3 Season

How a Sleeping Bag Works

These lifesavers called sleeping bags or mummy bags if you like are designed to lock up your body heat thereby keeping you warm in a cold environment.

These bags are essentially lightweight beddings made into a tube with a zipper to properly cover the user from the element and cold.

Sleeping bags work by the principle of thermal insulation which means that they do not generate heat of their own rather they insulate the person from the cold environment.

Sleeping bags conserve and distribute heat generated from the user’s body thereby keeping the person warm.

Some major parts of a sleeping bag include the insulation material stuffed within layers of cloth. The body of the bag is divided into compartments known as baffles which help control heat transfer within the bag. It has a covering or shell usually made of non-absorbent material or water-resistant coating.  

If you’re preparing for camp and expecting extreme cold weather, you definitely want to consider the following when picking out the right sleeping bag.

Factors to Consider When Choosing a Sleeping Bag

1. Insulation Material 

There are different types of insulation materials used in the manufacture of sleeping bags. They can be natural insulation like the down made from duck or goose feathers or synthetic insulation. Each has its advantage over the other.

Down insulation is known to provide more warmth (or thermal insulation) than synthetic insulation when measured by its warmth-to-weight ratio.

Synthetic insulation, on the other hand, is known to perform better in wet and humid conditions as they are not easily affected by moisture.

Lightweight cold weather sleeping bag tip: Choose down insulation made from duck feathers as it has the best warmth-to-weight ratio.  

2. Insulation Compression (Fill Power)

The fill power of a sleeping bag insulation is simply the amount of insulation material packed into a unit volume of the bag. This is measured by the ounce of insulation material that fills one cubic inch of the bag.

Typically, fill power can range from 450 for the less packed to 900 which provides the most warmth from lighter insulation material.

Tip: Choose a bag of at least 800 fill duck down.

3. Shell Material

The fabric of the outer covering is an equally important factor to consider when choosing a sleeping bag to purchase. Some bags use breathable fabrics while others use waterproof materials. Waterproof materials are good for wet conditions.

Extreme Cold Weather Tip: Choose durable water repellent (DWR) coated shells.

4. Shape and Size of Sleeping Bag

Sleeping bags come in different shapes although the very common ones are the quilt style and mummy-shaped style. While the quilt style is similar to a down comforter with a zipper, the mummy-shaped hugs around the neck region reduce excess space.

As for the size, the smaller the excess space inside the bag, the warmer it will likely be. It is important to choose one that fits you right and allows just enough space to move about in it.

Also, ladies will find the female sleeping bags better fitting than the general unisex bags.

The best cold weather sleeping bag tip: A mummy-shaped, fitting and slightly heavy sleeping bag with a durable zipper is preferable for extreme cold.

5. The Weight of a Sleeping Bag 

The weight of a sleeping bag is determined mainly by the type and quantity of insulation material used and of course the size of the bag.

It follows therefore that heavier sleeping bags that use good insulation materials tend to provide more warmth.

Good sleeping bags for cold weather tip: Unless you’re on a long hike, choose a quality sleeping bag irrespective of the weight.

6. Temperature Rating of Sleeping Bag 

This is the most important criterion when choosing a sleeping bag. There are 2 well-known rating systems—the seasons rating and the European standard rating.

Three seasons rated bags are most commonly available. They can be used during the spring and autumn seasons when nights can get very cold but not freezing. During summer, they can be used with the zip slightly opened.

One-season and two-season bags are better suited for warmer nights while the four-season bags are designed for cold temperatures of late autumn and spring. 5 season bags are suited for extreme cold and intense snow.

The European EN13537 standard uses ratings like the comfort rating, lower and upper limits, and the extreme rating. A detailed description of the various ratings can be found here 

Extreme cold weather sleeping tip: Choose a 4 or 5-season bag with a comfort rating of 10 degrees Celsius for extreme cold. 

• What does the temperature rating mean on a sleeping bag?

This is the lowest temperature at which a standard man can sleep in the bag for a night, also called comfort rating.

• How do you stay warm in a sleeping bag?

This is through thermal insulation created by the insulation materials locked inside the shell. It basically retains the user’s body heat.

• What is the best winter sleeping bag?

The best winter sleeping bag will have a 4-5 season rating, a temperature rating of 10 degrees, and ideally, down insulation of 800 and more.

If you follow our Extreme Cold Weather Tips you’re sure to arrive at the best pick.