Is my trip going up too fast?
Pace a trip by where you sleep, night by night. Red nights break the CDC's rules, and one tap shows the change that clears the most.
Add one night in Denver before Breckenridge. That clears 1 of 1 flag.
- Night 1ft
A first night at 9,600 ft from under 4,000 ft. The CDC's line is under 9,000 ft for the first night.
- Night 2ft
- Night 3ft
- Night 4ft
- Night 5ft
- Night 6ft
- Don't go higher to sleep if you have symptoms.
- Go down if the symptoms get worse, even with rest.
- Going down about 1,000 ft (300 m) usually helps quickly.
Your oxygen number can't clear you to go higher: people with symptoms usually show a number that's normal for the altitude. For higher-risk trips, the CDC names a preventive medicine your doctor can prescribe, acetazolamide.
The morning check
After 6 hours or more at a new elevation, rate each one. It's the 2018 Lake Louise score.
| Night | Where | Sleeping at | Headache | Stomach | Tired | Dizzy | Total |
|---|---|---|---|---|---|---|---|
| 1 (flagged) | Breckenridge | 9,600 ft | |||||
| 2 | Breckenridge | 9,600 ft | |||||
| 3 | Breckenridge | 9,600 ft | |||||
| 4 | Breckenridge | 9,600 ft | |||||
| 5 | Breckenridge | 9,600 ft | |||||
| 6 | Breckenridge | 9,600 ft |
What your result means, and what to do next
- Red nights sleep higher than the CDC's pacing allows. The suggested change is the one that clears the most of them, usually an extra night lower down.
- The risk band comes from your highest night. At medium or high, ask your doctor before you go, since the CDC names a medicine doctors can prescribe for higher-risk trips.
- The morning check is for every day up high. A score of 3 or more with a headache means don't go higher today, and go down if it gets worse.
Print the trip card and take it with you. Your oxygen number can't clear you to climb, so the card goes by symptoms.
How it works
The CDC paces a trip by sleeping elevation. From under 4,000 feet (1,200 m), don't sleep at 9,000 feet (2,750 m) or higher the first night. Above 9,800 feet (3,000 m), sleep no more than 1,650 feet (500 m) higher than the night before, and add an extra night for every 3,300 feet (1,000 m) you climb.
The risk band is the CDC's, by your highest night: low under 9,000 feet, medium to 11,150, high above. The CDC's table also counts past altitude sickness, so a yes moves the band up one step. The tool never predicts who gets sick.
The morning check is the 2018 Lake Louise score: headache, stomach, tiredness and dizziness, each 0 to 3, after 6 hours or more at a new elevation. 3 or more with a headache is a yes. Symptoms usually start 2 to 12 hours after you arrive. Your oxygen number can't clear you to climb, because people with symptoms usually show a number that's normal for the altitude. Preset elevations are rounded and approximate.
4 sources
- CDC Yellow Book, High-Altitude Travel and Altitude Illnesscdc.gov
- Luks AM and others, Wilderness Medical Society clinical practice guidelines for the prevention, diagnosis and treatment of acute altitude illness, 2024 updateeuropepmc.org
- Roach RC and others, The 2018 Lake Louise Acute Mountain Sickness Score, High Altitude Medicine and Biology, 2018pmc.ncbi.nlm.nih.gov
- Honigman B and others, altitude sickness in 3,158 visitors to Colorado resorts, Annals of Internal Medicine, 1993europepmc.org
