There are a number of factors you need to consider when reviewing a sleeping bag, the most important one by far is whether the bag’s temperature rating is sufficient for your needs. Here’s what to look for.
What’s your sleeping bag rating?
Sleeping bags usually have two types of rating – season or temperature. There are three options for the season rating: two season, three season and four season. This is intended to give you a broad idea of when the bag should be used. For more information you need to look at the temperature figures. The most important temperature figure is the comfort temperature or lower comfort temperature depending on how the manufacturers have displayed their data. Often the sleeping bag has a comfort range, the minimum temperature is the lowest the temperature can get down to before you start feeling cold. Other manufacturers show the information has three figures: Comfort/Limit/Extreme. ‘Extreme’ is the absolutely lowest temperature the bag should be used at. ‘Limit’ is when you will begin to feel very cold. ‘Comfort’ is the ideal working temperature for the bag.
To make sure you’ve got the right bag, compare the comfort rating to the normal night time temperatures of your destination. For example, in Oregon in February the average nightly temperature is -5.1 degrees C and in July it’s 7.9 degrees C. Compare this to the United Kingdom where the February figure is 1.1 degrees C and in July it’s 11.7 degrees C. Be sure to get a sleeping bag with the correct rating for your destination. In winter, to be on the safe side, I’d definitely look at the ‘Extreme’ rating of the bag and compare it to the lowest record temperatures of a region.
Cold or warm sleeper?
Do you sleep in your bed socks in July? If you do I’m willing to bet you’re a cold sleeper. If you’re a cold sleeper I would certainly adjust all the figures down. Go for the three season sleeping bag in summer and the four season one in September. Women, in general, need a sleeping bag that’s 5 degrees lower than men as do older people. Manufacturers assume you’re going to be wearing baselayers or reasonable pyjamas while sleeping, if you prefer to go naked, again, adjust the figures.
Down filled sleeping bags are the best quality sleeping bags you can buy. They’re lightweight, they pack down really small and they have the best weight to warmth ratio of any bag. The problem is they’re very expensive and, if you’re a family summer camper, they’re way over the top. Family campers should stick with the synthetic bags. They may be a little bulkier and a bit heavier but they still provide all the warmth that you need and, here’s the exciting bit, they’re a lot cheaper.
What you are sleeping on will affect your warmth and your sleep. A lot of heat is lost into the ground so make sure your mat is insulated. Also make sure the sleeping bag fits, so have a look at the dimension before you buy. Mummy shaped sleeping bags fit more snuggly and will therefore keep you warmer. Square or Envelope sleeping bags aren’t quite as warm but they give you more room to kick your legs about.