There are risks in going to high altitude and it's important to understand these risks. The summit of Mauna Kea is a hostile and potentially hazardous working environment. All Gemini staff needs to pass a strict medical examination in order to be allowed to work up at the telescope. This medical certificate will not be required for observing visitors; however, Gemini will require that all visitors prior to going to Mauna Kea sign a medical disclaimer. This disclaimer transfers the emphasis of awareness of the potential medical difficulties and their symptoms from the administration directly to the observers themselves. It is the observers' responsibility to ensure they are sufficiently healthy to work on Mauna Kea.

Altitude sickness is primarily caused by a lack of oxygen - hypoxia. At the summit of Mauna Kea, the oxygen content of the reduced atmosphere is a mere 60% of that at sea level. The major cause of altitude illnesses is going too high too fast. A preventive measure to altitude illness is acclimatization. Your body can adapt to the decrease in oxygen at a specific altitude in 1-3 days. Gemini requires that all observers take about one hour to drive from Hilo to Hale Pohaku, and then acclimatize at Hale Pohaku (9,300 feet) for 24 hours before proceeding to the summit.

Keep in mind that different people will acclimatize at different rates. Make sure all of your team members are properly acclimatized before going higher. Stay properly hydrated, so drink lots of fluids 24 hours before, during, and for 12 hours after your trip to the summit! Take it easy - don't over-exert yourself. Avoid tobacco, alcohol and other depressant drugs. Eat a high carbohydrate diet while at altitude. Avoid gas producing food the day before and the day of your trip.

Remember, the cure for altitude sickness is an immediate descent to a lower altitude: Hale Pohaku, or even sea level!