Here at Therm-a-Rest we are a bit obsessed with sleep systems, we hoot and holler about them all the time at HQ. I would call it our mission to design the perfect sleep system, but it’s bigger than that really, it’s more of a quest.

We don’t mean to be dramatic, but we are acutely aware that comfortable night’s sleep outdoors can be the difference between elation and misery. Here we will walk you through building the right sleep system by showing you how to match sleep equipment to individual preferences as well as the conditions present.

What is a Sleep System?

Oxford dictionary defines a system as a set of things working together as parts of a mechanism or an interconnecting network; a complex whole. A sleep system then, is the sum total performance of the things you use to achieve a good night’s sleep outdoors. It can be broken down into three component categories: Insulation, Pad, and Clothing.

1. Insulation:

One common thing that comes to mind when pondering outdoor sleeping is zipping yourself up in a warm sleeping bag and enjoying a plush human cocoon. This is the insulation component and it is the core of your sleep system.

Traditionally, sleeping bags have been the sole choice for the adventurer in terms of insulation, but in the past few years quilts have risen in popularity due to their lighter weight and targeted design. Both sleeping bags and quilts use either down or synthetic fill to insulate and achieve their EN/ISO temperature ratings. Picking the right fill type, the appropriate temperature rating, and the right size is how you arrive a solid choice for component #1.

2. Sleeping Pad:

By inventing the self-inflating mattress in 1972 Therm-a-Rest did wonders for sleep systems long before anyone was calling them sleep systems. They dramatically improved outdoor sleeping by creating a cushioned yet stable surface, and providing much more insulation than the thin closed cell foam pads of the day.

It has been nearly a half century since the Original Therm-a-Rest and let’s just say sleeping pad options have expanded. You can still sleep on closed cell foam if that’s your style, our classic Z Lite™ SOL is a popular choice for that. You can also explore the myriad of self-inflating open cell foam designs we offer, or for those looking to limit pack size and weight, our NeoAir® series offers superior warmth-to-weight ratios.

It is important to take a close look at the R-Value of any pad because this measures how much the pad insulates you from the ground; the higher the number the more insulation the pad provides. If finding your perfect sleeping pad feels daunting, we put together a handy sleeping pad finder to help guide you through the process.

3. Clothing:

When measuring the EN/ISO temperature ratings of sleeping bags, the sensor-loaded mannequin that tests the bag is wearing clothes. That’s right, it is wearing base layers, which means sleeping bag temperature ratings assume that a real user is wearing clothes. Base layers are critical to staying comfortable all day and all night.

A warm hat and fresh socks stave off frigid temps, while a dry base layer ensures that your sweat doesn’t leave you chilled.

4.Bonus Category: Pillow!

Not much to explain here. Even if you have limited space in your pack, you can fit the Air Head™ Lite in your pocket on the way out the door. Gone are the days of waking up in the middle of the night with the zipper of your jacket pressed against your head, Therm-a-Rest has you covered with our lineup of backcountry ready pillows.

What Does a Sleep System Do?

Being warm, or simply just the right temperature, is called thermal efficiency and it is achieved by a system that provides the right amount of insulation and breathability, but it is not the only upside.

Dialing in your sleep system saves weight with more efficient gear choices. It saves energy by protecting you from harsh conditions to maximize the value of your body heat. It fulfills the number one rule of recreating outdoors: being prepared. The right gear provides the versatility to keep you comfortable in a wide range of conditions.

Building your Sleep System

What then is my ideal setup you ask? That depends both on your personal preferences and the nature of the adventures you are undertaking. The components of a sleep system should meet the demands of the sleeper and overcome the challenges of the natural environment.

It is helpful to look at sleep systems as a function of the seasons to get the big picture of combining the different pieces for the sum effect. It is possible to use a maximum of four pieces of gear—two pads, one sleeping bag and one quilt—for all four seasons.


Mild summer nights give you the flexibility to pare down your kit and shed weight. A quilt offers customizable breathability and a NeoAir® XLite® provides plenty of ground insulation.
Summer System:

  • NeoAir® XLite®
  • Vesper™ 32F/0C


Dwindling temperatures demand more warmth, it is time to break out your trusty down sleeping bag. Consider adding a closed cell foam pad to boost your ground insulation.
Fall System:

  • Z Lite™ SOL
  • NeoAir® XLite®
  • Parsec 20F/-6C


Winter camping means it’s time to carry more weight and plan a bit harder to stay warm. Layering your sleeping pads and adding a quilt over your sleeping bag will make it hard to leave your cozy tent in the morning.
Winter System:

  • Z Lite™ SOL
  • NeoAir® XLite®
  • Parsec 20F/0C
  • Vesper™ 32F/0C


Despite the promise of warming temperatures and thawing landscapes, the rain, snow and cold weather linger. You can both be prepared and lighten your load by simply leaving the extra pad at home.

Spring System:

  • NeoAir® XLite®
  • Parsec 20F/0C
  • Vesper™ 32F/0C

Finding Your Comfort Level

No matter which season, the components of a sleep system should meet the demands of the sleeper and overcome the challenges of the natural environment.

For example, if you are a side sleeper in the Pacific Northwest, where it rains a considerable amount, then you may want to consider a roomier fitting, synthetic fill sleeping bag. The Saros 20F/-6C would fit this description with its water resistant eraLoft™ synthetic fill, and its accommodating fit. If you wanted to go with down fill you would simply have to take extra precautions to keep your bag dry or risk losing insulation capabilities.

Understanding your own brand of comfortable sleep is critical. If you sleep warm, perhaps you can save weight by utilizing the quilt. If you sleep on your side, look for pads that are at least 2 inches thick and sleeping bags that allow you generous range of movement. Those minimizing pack weight on a multi-day backpacking trip may select an entirely different system than those doing a quick and comfy overnighter in the same season, with similar weather.

I have spent a considerable amount of time at high altitudes in Colorado, where a balmy day in August can be a winter affair by sundown. Cloudless skies become harassing thunderstorms in the early afternoon. By carrying a system appropriate for a shoulder season, fall or spring, I feel confidently prepared I can end each day with the rest needed to take on the next.

We understand that no two sleepers are alike just as no two trips present the same challenges. The Therm-a-Rest line of sleeping pads and bags has been developed to meet individual needs across the globe. Whether you are pushing into the high alpine or crashing in the backyard with your kids, you can find your ideal sleep system at Leave us a comment about your ideal sleep system!