Skip to main content

Resting well and getting the best sleep possible while in the mountains is important to making sure you have the energy for the following day’s adventure. That’s why having a sleep system that keeps you warm, comfortable and lets you rest well is of the utmost importance in the backcountry.

When talking about sleep systems we are referring to sleeping bags and sleeping pads. There are many different types and brands when it comes to sleep systems but below, we will go over important information to consider for any sleep system.

Sleeping Pads

There are two general types of sleeping pads: inflatable and foam. Both have their pros and cons and are often used together!

Foam pads on one hand are durable and insulate extremely well but are not always the most comfortable.

Inflatable pads on the other hand are very comfortable pads, insulate well on dirt but are more prone to getting holes or popping.

For early season when we are often sleeping on snow or in late season when temperatures drop, we often encourage climbers to use both a foam and inflatable pad to keep warm and be as comfortable as possible. When using two pads the foam pad goes on the bottom to insulate against the snow and the inflatable pad goes on top to create a comfortable and warm surface to sleep on.

In Mid-season when temperatures are warmer, and we are often no longer sleeping on snow you can decided between the foam and inflatable pad. The foam is great to bring because they are super durable and light. On the other hand, the inflatable pads are often more comfortable but can deflate or pop if sleeping on a very rocky surface. It is up to each person to decide in mid-season which pad they prefer to use based on terrain, weather, and conditions.


Important things to consider when understanding sloping pads is the R-value of the pad. The R-vale translates to the sleeping pad’s ability to resist heat flow through the pad. There are two important factors to understand when considering the R-vale of a sleeping pad.

  • First is that the higher the R-value of a pad the better it will insulate from cold surfaces. R-values usually range from less than 2 (minimally insulated) to 5.5 or more (very well insulated).
  • Second, is that the R-vales are additive meaning that by sleeping with two pads you increase the R-value (aka warmth) of your sleep system.


For packing sleeping pads make sure that inflatable pads are inside your pack and not near anything that could potentially poke a hole in it such as crampons, camping stove, pocketknife etc. Foam pads on the other hand are best on the outside of the pack as they are bigger and double as a great seat to pull out and sit on during breaks.


At our Guide Hut we have both foam and inflatable pads that we rent or sell to clients for climbs in the Cascades:

  • Foam: The Thermarest Z-lite Sol is a foam pad that has an R-value of 2.0 making it great to use on its own in warm weather or by using it with another pad when sleeping in colder weather or on snow.
  • Inflatable: The Thermarest Prolite Plus is an inflatable pad that has an R-value of 3.2 making it warmer than the Z-lite and great for using on its own in warmer weather and on relatively smooth surfaces or pairing up with a foam pad on colder or snowy surfaces.

Thermarest Prolite Plus

The Thermarest Z-lite Sol

Sleeping Bags

When it comes to sleeping bags there are two main fillings: down and synthetic. Both have their pros and cons.

Synthetic bags are great because even if they get wet, they don’t lose their insulative properties so they can be exposed more to the conditions. However, they are quite bulky when trying to pack and they aren’t quite as warm as a down sleeping bag.

Down sleeping bags on the other hand are very warm and true to their ratings, as well as easy to compress to make packing easier. However, if down bags get wet, they lose their insulative properties very quickly and therefore no longer serve their purpose. If you are looking into purchasing a down sleeping bag, make sure to check out our blog about understanding down products!

Time of year/where you are going

Before heading out for you mountaineering trip make sure to research the weather and conditions for the time of year you will be there, especially the temperatures at night. This will help you decide what kind of sleeping bag and sleeping pads you will need.

It is often advised when buying a sleeping bag to buy one 10 degrees warmer than the average night temperatures where you are going since it is always easier to manage the sleeping bag being too warm (you can unzip it) than it being too cold.


We recommend getting a compression sack for your sleeping bag if it doesn’t come with one. Compression sacks are a great way to stuff a sleeping bag and minimize the volume of it. When packing your sleeping bag inside your backpack make sure that it is inside a water proof bag (checkout out blog on packing a backpack) so that it doesn’t get wet as you are hiking.

Understanding Ratings

When looking at sleeping bags there are often three ratings that are found inside the zipper: the ISO rating, the comfort rating, and the extreme rating.

The ISO or En temperature rating in sleeping bags refers to the rating on your sleeping bag in a lab setting where the bags are tested with a dummy. Not all company test this way but if they do all their bags are tested under the same controlled conditions.

The comfort rating refers to the temperature at which you’re likely to be the most comfortable in the sleeping bag. This varies between women and men’s sleeping bags and often bags will list a comfort rating for both men and women. This is based on the idea that most women sleeping colder than men do but it is very subjective and varies person to person.

The extreme rating on sleeping bags refers to the absolute minimum temperature you can survive in the sleeping bag without getting hypothermia. This doesn’t mean that one would be warm or even be able to sleep but that you could survive in it in an emergency.

For our Mount Baker trips in the early (April – June) and late season (September) we recommend that climbers use a sleeping bag with a comfort rating of 0 degrees Fahrenheit to stay warm and sleep well at night. In mid-season (July and August) climbers can use a 20–30-degree F comfort rating and stay warm as the temperatures don’t often drop too low in mid-season.


In our Guide Hut we rent and sell the Thermarest Questar zero degree down bag which is a great allrounder for PNW climbs as it keeps you warm in early and late season climbs and can be used on warmer mid-season nights by unzipping it. They are down so they pack very small and don’t weigh much.

Thermarest Questar

The size of a Thermarest Questar in a compression sack

Sleep systems are an important part of any overnight adventure and can vary from person to person in terms of comfort and needs. Finding a sleep system that is appropriate for the area in which you are recreating allows you to get the best rest possible for your adventures in the outdoors!