Camped at the base of Gannett Peak, tomorrow's ascent into the clouds taking up most of your thoughts, you're brought back to earth by a student with a complaint. No, it's not your cooking that's bothering him, it's his head and his stomach. His head hurts, his stomach doesn't want to hold down food, and, on questioning, he reveals he hasn't been sleeping well and, in fact, he really thinks this whole NOLS thing sucks. Obviously he is unwell but nothing about his physical appearance alarms you. His heart rate and respiratory rate are elevated, but not to the point where the numbers are a big surprise. You are, after all, sitting well above sea level.

Well above sea level! Aha! You test the student for ataxia and he fails the test. Time for descent of at least one thousand feet. On full recovery, you may consider a return to the heights. Without a full recovery, you'll want to keep descending.

When you go higher in altitude, the amount of oxygen available in each breath grows lower. If you go too high too fast, unhealthy physiological responses may occur. Right out of the starting blocks, altitude illness should be on the list of possible explanations for your student's problems. For simplicity, these problems can be divided into two categories: mild and severe.

Anyone coming from lower altitudes to 8,000 ft. or more may complain of headache, unusual fatigue, nausea, loss of appetite, difficulty sleeping, unusual shortness of breath when exercising, and lassitude - all symptoms of mild altitude illness. The best treatment is: Do not go up until the symptoms go down. Exercise lightly and drink plenty of water.

Maintain a diet high in carbohydrates. Acetazolamide may be used for treatment after symptoms appear. Do not use acetazolamide if the patient is allergic to sulfa drugs. If the symptoms do not go down within two days, the patient should.

Untreated, mild illness may progress to severe. The most important early sign of this progression is ataxia (loss of coordination). An ataxic patient cannot walk a straight line or stand straight up with feet together, hands pressed into the thighs, and eyes closed. Severe altitude illness may show up as High Altitude Pulmonary Edema (HAPE): constant shortness of breath, chest pain, productive cough, and very fast heart rate. Or it may show up as High Altitude Cerebral Edema (HACE): severe headache unrelieved by rest and medication, bizarre changes in personality, perhaps coma. Or it may show up as some of both. The patient needs to go down as soon as possible. In addition to descent, the best treatment is supplemental oxygen. Treatment may also include 1) the drug nifedipine (sold often as Procardia®) for HAPE. 2) The drug dexamethasone (sold often as Decadron®) for HACE. If descent is delayed, use of the Gamow Bag®, a portable hyperbaric chamber that simulates descent, may save the patient's life. Do not use a Gamow Bag® instead of descent. If your assessment is HAPE or HACE, the patient needs evacuation from the field for a physician's assessment.

For more information on wilderness medical training, check out wmi.nols.edu.