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with the aid of the Sun's rays. These body reserves will be adequate as long as the general mode of living throughout the year is not enervating.
Conductive heat loss should be prevented as much as possible. If one sits on cold ground something insulating material should be placed on the ground so one does not lose heat and not touch a metal either. Special care should be taken to properly cover the hands and head. A significant amount of heat is lost through the head and hands since there is an abundance of blood vessels in these areas. A scarf or similar should be put in front of mouth to pre warm the cold air, as cold dry air is one of the recognized asthma trigger. Wear cap preferably with ear protection. One is at risk for frostbite at temperatures below at which extreme caution should be taken to protect the skin from exposure, thus limiting the chances of developing frostbite. Early symptoms of frostbite include a tingling, stinging, or aching feeling in exposed area followed by numbness.
Clothing: Air-hygiene concerns the skin quite as much as the lungs. Air may be shut out not only by tight houses but also by tight clothes. Therefore the hygiene of clothing assumes a new and unsuspected importance. The hygiene of clothing includes ventilation and freedom from pressure, moderate warmth and cleanliness and allows free access to air to the skin. Loose, porous clothing allows free access of air to the skin.
Cold weather requires considerable care in dressing. Those who have learned to clothe themselves properly find that they have grown far more independent of changing weather conditions. Only the minimum
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