Immediately descending to a lower elevation. If you're climbing or traveling at high altitudes and have mild symptoms of HAPE, descend 1,000 to 3,000 feet (about 300 to 1,000 meters) as quickly as you can, within reason. Depending on the severity of your condition, you may need rescue assistance to get off the mountain.
It's always a healthy idea to stop smoking. If you need help quitting, talk to your doctor. He or she can provide tips and, sometimes, medications to help you quit smoking.