Joanne Richardson, Coroner for Summit County, Colorado, includes within her jurisdiction the Breckenridge (2925 m), Copper Mountain (2960 m) and Keystone (2835 m) ski resorts. She advises visitors to take aspirin 325 mg/day, starting two weeks before they arrive and continuing for the duration of their stay. They should also ensure they drink plenty of water to avoid dehydration. The risks are not confined to skiers: mountain bikers and hikers are also susceptible.

Several deaths occur every year in high altitude ski resorts. Some involve people who already have heart disease, and many reportedly occur in the under-40s. Visitors to high ski resorts can put their cardiovascular system under extreme pressure: unaccustomed severe exercise, late night parties and increased alcohol consumption worsen the effects of the low oxygen pressure at altitude. This may be enough to precipitate a heart attack in people who have heart disease, some of whom will be unaware of their problem. Some visitors also have to cope with altitude sickness during the first few days of the holiday.

This advice from United States officials is based on empirical observation and experience. Long-term use of low-dose aspirin (75 - 150 mg/day) lowers the risk of heart attack. It is recommended for people who have had a stroke, a heart attack or bypass surgery, and for people at high risk but who have not yet had overt disease. There is no published evidence that short-term use of aspirin reduces the risk of heart attack associated with high altitude sports. Neither the British Mountaineering Council nor the Ski Club of Great Britain make any recommendations about using aspirin.

aspirin can also prevent headache associated with sudden exposure to altitude. Clinical trials have shown that taking analgesic doses (320 - 960 mg 4-hourly) shortly before arrival at altitude can reduce the incidence of headache by as much as 40% compared with placebo1, 2. These studies lasted only 1 - 2 days.

References
1. Burtscher M et al. Effects of aspirin during exercise on the incidence of high altitude headache: a randomized, double-blind, placebo-controlled trial. Headache 2001;41:542-5

2. Burtscher M et al. aspirin for prophylaxis against headache at high altitudes: randomised, double-blind, placebo-controlled trial. Br Med J 1998;316:1057-8