EUROPEAN STANDARD EN 13537
All of our sleeping bags are tested to EN13537 2012 European standards and EN ISO 23537-1:2016 by an independent textile research body. A special mannequin, fitted with sensors, is inserted into the sleeping bag and identifies the optimum user temperature according to the temperature of the environment.
DEFINITION OF COMFORT AND EXTREME VALUES
- Maximum comfort temperature. This is the maximum temperature that allows a standard man to sleep without perspiring excessively. It is established with the sleeping bag zips and hood open and the arms outside.
- Comfort temperature. This is the temperature level (referred to a standard woman) at which it is possible to sleep all night in a relaxed position.
- The lower comfort limit is the minimum temperature (referred to a standard man) at which it is possible to sleep in a curled up position, without waking, for eight hours.
- Extreme temperature. This is the minimum temperature at which the sleeping bag protects the user (standard woman) against hypothermia. It allows six hours of uncomfortable sleep without the internal temperature dropping to a dangerous level.
When you choose your sleeping bag, we suggest that you consider comfort and intermediate temperatures, according to your level of physical fitness. When we feel hot or cold, it is caused by our body producing greater or smaller amounts of heat compared to what we are losing to the surrounding environment.
THE MAIN PHYSIOLOGICAL FACTORS THAT INFLUENCE FEELINGS OF COLD/HEAT:
- Metabolism: a sleeping person generates 75-100 Watts of heat, depending on different factors such as age, sex, weight, habits and psychological and physical conditions.
- Weight: overweight people usually have a slower metabolism. They generally eat more than they consume. During mountaineering activities, we usually take in fewer calories than we consume. Overweight people are able to use energy from their fat reserves and they also have greater natural insulation than thinner people.
- Age: metabolism is linked to age. An older person generates less heat and therefore, s/he will feel the cold before a younger person does.
- Sex: women generally feel the cold more than men; so much so that the standard comfort temperature for women is 5°C higher than for men.
- Habits: the majority of people in the western world lives in centrally heated houses, works in airconditioned offices and moves around in air-conditioned vehicles. This lifestyle reduces the body’s ability to withstand the cold.
- Experience: experience and familiarity with equipment for sleeping outdoors helps the user to get the best from it. Novice users will generally feel greater discomfort and cold than experienced people.
- Physical fitness: if we lead a sedentary lifestyle and we submit ourselves to a tiring excursion, we will immediately become aware of the fatigue. Fatigue reduces heat production and this leads to our feeling cold.
When you choose a sleeping bag, make sure it is suited to the type of activities you think you will be carrying out, considering the temperature, humidity and also the size and weight of the sleeping bag.
- Invest in a good mattress/airbed since as well as helping you to sleep comfortably, it will also provide you with adequate insulation from the ground.
- Buy a good tent to protect you against bad weather. Sleeping in conditions where you are directly exposed to wind and/or particularly damp conditions will lead to a considerable increase in body heat loss through convection.
- Always check the long-term weather conditions as they can change suddenly and the equipment you chose on departure could well be unsuitable in the event of worsening weather.
- Take extra clothing which can be worn under normal clothes in case of cold as well as serving at night. Moreover, if you expect temperatures to fall below zero, take a balaclava and bivouac socks.
- Eat correctly otherwise your body will generate less heat and you will become more sensitive to the cold as a result. Drinking is also very important as dehydration reduces the body’s ability to produce heat. Avoid alcohol, as this only gives an initial sense of heat, leaving you feeling colder than before.
- Keep your equipment dry since wet sleeping bags (especially when filled with down) offer less insulation than dry ones. This is why Sandfox provides watertight stuff sacks as standard with different sleeping bag models to protect them against damp. In any case, dry your bag in the open air as soon as possible, leaving it on the top of your tent during the day, for example. Air your tent whenever possible, maintaining an air exchange that can reduce the problem of condensation.