Spend a few days at 5000 to 7000 feet before journeying to the high country. Take it easy on the day of arrival. Gradually increase the amount of exertion during the second and third days. Avoid dehydration by drinking a lot of fluids. While mountain climbing, gain only 1000 feet per day.
Breathing becomes labored or fast.
A headache becomes severe. Vomiting has occurred three or more times. Your child starts acting very sick. You have other questions or concerns.