Altitude Sickness One of the most common problems for hikers is altitude sickness, which results when a hiker ascends to heights over 8,500 feet without being properly acclimated. To help prevent altitude sickness, spend a night or two at the higher elevation before attempting any strenuous physical activity, and if you have a history of heart or circulatory problems, talk to your doctor before planning a visit to areas at high altitudes. Symptoms of altitude sickness include headache, nausea, vomiting, shortness of breath, weakness, and sleep disturbance. If any of these occur, it's important to retreat to a lower altitude . Acclimatization and Illnesses Great information from Princeton University's Outdoor Action program.
Symptoms are chilliness and fatigue, followed by shivering and mental confusion.
The minute these signs are spotted, get the victim to shelter of some kind and wrap him or her in warm blankets or a sleeping bag. Ideally another member of the party should get in the sleeping bag with the victim for added warmth. If practical, it's best for both people to be unclothed, but if clothing remains on, it must be dry. High-energy food and hot drinks also aid recovery. To avoid hypothermia, always carry warm, dry clothing, avoid immersion or exposure to cold water or rain, and keep energy levels up by eating high-calorie foods like trail mix.