It's highly recommend to stop at the Visitor Information Station at 9,200 ft to receive a current weather update, safety information, and to adjust to the change in altitude. Mauna Kea is one of the only places in the world where you can drive from sea level to 14,000 feet in about 2 hours, so altitude sickness is a high possibility. At 14,000 feet, there is 40% less oxygen than at sea level, so visitors should acclimatize to the altitude before proceeding further up the mountain. Anyone in poor health should consult their physician before planning a visit to Mauna Kea.