Sleeping bags are all about comfort, right? I mean, we talk about liquid capacity and versatility of hydration packs, weight and durability of camping backpacks/hiking packs, and size and weight limit of hammocks for hiking and camping.  We like to talk solely about comfort when it comes to sleeping bags.  One very large comfort factor of camping is how warm you are-in and out of the bag.  That’s what we’ll focus on for this quick guide.

Understanding the Standards of Temperature Ratings

When shopping for, or researching, your next (or first) sleeping bag, you’ll notice that they always have a temperature or set of temperatures associated with it.  These temperatures indicate the lowest temperature at which the sleeping bag should keep a person warm.  For example:  A brand sleeping bag of 35 degrees F should keep a typical person warm at temperatures of 35 degrees and higher (warmer).

Please note, this rating is measured with a few factors.  It assumes that the person in the sleeping bag is wearing a pair of long underwear and with a decent quality sleeping pad under them.  (Sleeping bags form an insulation barrier between the cold ground preventing it from sapping body heat)

Here’s the thing, though, sleeping bag insulation and ratings vary from brand to brand and make to make.  Also, the rating does not take into account the large variances in everyone’s metabolism.

How Does Metabolism Affect Body Temperature: People who work out or exercise increase their metabolism and the body gets warmer and sweats.  People metabolism at a resting or normal rate vary greatly.  Thus, a person with a higher metabolism will be warmer inside of a sleeping bag.

Here’s a Quick Chart for Sleeping Bag Temperature Rating Reference:

Type of Sleeping BagTemperature Rating Definitions

Summer Season Sleeping Bags

+35 degrees F and warmer (higher)   Example:  TETON Sports Journey 35+ F Ultralight Sleeping Bag

3- Season Sleeping Bags

10 degrees F to 35 degrees F   Example:  GEERTOP® Comfort Lightweight Envelope Sleeping Bag

Winter Sleeping Bags

+10 degrees F and colder (lower)   Example: TETON Sports Celsius XL