You will typically see two temperature ratings quoted: the Comfort Temperature Rating and the Extreme Temperature Rating. What are they? What do they mean?

THE COMFORT TEMPERATURE RATING - is shown as a range e.g. +12°C to +25°C. The range is generally understood to refer to the ambient temperature around you. The first temperature quoted in this range is the lowest the manufacturer considers you will remain comfortable in. Naturally, the second value is the highest temperature that they consider you will remain comfortable in.

THE EXTREME TEMPERATURE RATING - is a single value and is generally understood to be the coldest temperature that an experienced user should use the sleeping bag in.

Although all sleeping bags have temperature ratings you should bear in mind the following:-

• Notions of warmth and what is a comfortable sleeping temperature are subjective. Be aware of this and let your knowledge of your own personal requirements influence your decision.

• There are no standard measurements of temperature ratings among sleeping bag manufacturers. Use the ratings as a reasonable guide only.

From the beginning of 2005, sleeping bags that meet the standard will display 4 temperature ratings:

• Upper Limit - highest temperature at which a standard MAN would have a comfortable nights sleep without sweating.
• Comfort - lowest temperature at which a standard WOMAN would have a comfortable nights sleep, lying on her back and relaxed.
• Lower Limit - lowest temperature at which a standard MAN in a rolled up body posture would have a comfortable nights sleep.
• Extreme - temperature below which a standard WOMAN could expect strong sensation of cold and maybe actual physical injury from cold (e.g. frost bite or hypothermia).