Forclaz 15° Light Hiking Sleeping Bag (Right Zip) - Purple

We label all of our sleeping bags with a "comfort temperature" which is tested by an independent laboratory (AITEX) in accordance with European standard EN 13537 of 11/04/2002. The "comfort temperature" is the lower temperature limit at which the user feels comfortable overall - neither hot nor cold - while lying in a relaxed position (temperature determined for an average woman under normal conditions of use). CHOOSE YOUR SLEEPING BAG ACCORDINGLY

Comfort limit temperature: The minimum temperature at which a user feels comfortable overall - neither hot nor cold - while huddled up in the sleeping bag (as determined for an average male user under normal conditions).

A sleeping bag does not produce any heat. Rather, it retains the heat produced by the body. If you are tired and cold and you slip inside a cold, damp sleeping bag, you will most likely feel cold no matter how good your bag!
These temperatures depend on a person's ability to withstand cold (build, fatigue, etc.), his equipment (insulating mattress, etc.), the way he is dressed (if he is naked, wearing underwear, etc.), and weather conditions (damp, wind, etc.).

Don't overdress (1 layer of clothes is enough)
Keep your extremities warm: use hats, gloves, socks, bed warmers, rubbing, etc.
A flask filled with hot water can be used as a foot or bed warmer (so long as there's no chance of it opening by accident!)
Contract your muscles (70% of the energy you consume is transformed into heat) without making movements that could cause a draught.

Wash your bag separately from other clothes or delicate colours, use 1/3 of a dose of washing powder, and select a synthetic cycle at 30°C. Stretch the bag out to dry in a dry, well-ventilated place out of the sun and away from heat sources or tumble dry low. Tip: a sleeping bag liner allows you to spread out washes and maintain good thermal performance.