Almost all sleeping bags on the market today come with a temperature rating that lets the buyer know what type of weather the bag has been created for. Manufacturers seem to make their best guess when rating summer sleeping bags as well as other kinds. However, these guesses are not standard over all brands. Therefore, when looking for cold weather ones, you may find that a 20 degree ones will actually keep you warmer than a 0 degree ones. This article will shed some light on the temperature ratings, which will help you understand the number when you are making a purchase.
The most important aspect about sleeping bags that you need to keep in mind is that they do not keep you warm. Instead, your body regulates the temperature of the bag so that you can sleep comfortably while inside it. The material does not to create or reduce heat by itself. Therefore, cold weather bags do not come with a heater installed, such as summer sleeping bags do not provide a fan or air conditioner. This means that they will actually differ in temperature between users, because it is dependent on the user's own temperature.
Several factors can help determine who would be warmer in one. If you have two people sleeping in the exact same brand and type, there is highly likely that one person will be more comfortable in regards to temperature. For instance, if person 1 has been in the woods several days already and has been getting plenty of sleep, liquids, and hot food, he may find himself 'warmer' then person 2 who has hiked 20 miles, ate granola bars, and is tired and thirsty.
Because of so many different factors that can alter the temperature of summer sleeping bags as well as others, manufacturers use the temperature ratings of their products as a general guideline. The score a certain bag is given is the minimum temperature that the bag is created for in order for the user to sleep comfortably. Also, the manufacturer assumes that when using one of their bags, you utilize other necessary accessories to ensure you get the temperature the bag has been rated. For example, when using cold weather bags, the manufacturer guesses that you are also using a tent, warm clothing, and a sleeping pad that are all designed for cold weather.
It is also important to note that the temperature ratings are for the sleeping bags when they are brand new. Over time, the bags will get worn out and lose their ability to keep in heat. Winter bags will, of course, do this quicker than summer sleeping bags which are already thinner by design. When shopping, consider the loft - thickness - and quality of the materials to determine which would be most appropriate for the conditions you will be using it in. This can sometimes be a more accurate judgment than the temperature ratings.