Free tool · 2,407 m and counting
San Pedro sits at 2,407 m; El Tatio at 4,320 m. Altitude is the one thing that can ruin an Atacama trip before it starts — so here is exactly when each kind of excursion becomes safe after you land.
Most travelers arrive on the morning bus or the Calama shuttle around midday. The timeline below shifts with your input — set your real arrival.
Each window is a different altitude ceiling. The clock shows your personal times from arrival.
Fri 14:00 → Sat 02:00
0–12 h · Settle in
Town only (2,407 m). Walk slowly, hydrate, skip alcohol and heavy food.
Take it easySat 02:00 → Sat 14:00
12–24 h · Easy evening
Evening/night plans ≤2,500 m: town walk, stargazing tour, sunset at Quitor.
Take it easySat 14:00 → Sun 02:00
24–36 h · Low tours OK
Valle de la Luna, Cejar, Chaxa (≈2,300 m). Still nothing above 3,475 m.
CautiousSun 02:00 → Sun 14:00
36–48 h · Mid altitude OK
Termas de Puritama (3,475 m) fine if day 1 was gentle. Watch how you slept.
Green lightKnow the difference
Mild symptoms are normal and settle in a day or two. Severe ones are an emergency — tick nothing, just descend.
Two or more mild symptoms? Water, no alcohol, no new excursions today. Better by tomorrow morning? Carry on.
Descend 300–500 m and wait. If symptoms improve within a few hours of going down, it was altitude. If they do not, or they worsen even after descending, it is something else — get to a doctor.
From San Pedro the practical descent is back to Calama (2,260 m) or further to Antofagasta (sea level). The medical center in San Pedro is the Consultorio Loros Rojos; serious cases are stabilized and transferred to Calama — about 1 h 30 by road.
Ask your doctor about acetazolamide (Diamox) before the trip if you have prior altitude problems — it must be started the day before arrival, and it does not replace the 72-hour rule.
The trip planner already sequences every itinerary low→high: easy arrival evening, low tours on day 2, high plateau only from day 3.
Straight answers
What the tea actually does, what day 2 really feels like, and why 'I feel fine' is not a plan.
A little, honestly: it is a mild stimulant that can take the edge off a first-night headache, and drinking warm fluids is never a bad idea at altitude. But it is comfort, not medicine — it does not prevent acute mountain sickness, and chewing coca leaves will not turn a day-1 El Tatio plan into a safe one. Enjoy the ritual; respect the 72-hour rule.
For the classic itinerary: 48–72 hours before tours above 3,900 m, and most people feel noticeably better after the second night. Sleep quality is the best gauge — when you stop waking up gasping (normal periodic breathing at altitude), you are adapting.
We will not schedule it, and neither should you. A 4 a.m. departure, –5 °C, and 4,320 m after one night at 2,407 m is the most common recipe for a ruined trip. Day 3 onward it is unforgettable — that is exactly what the trip planner enforces.
No — acute mountain sickness typically peaks 6–12 hours after arrival, which is why the first evening feels deceptively easy. The arrival-day plan (town walk, early dinner, stargazing instead of summit hikes) exists precisely because of that delay.
Symptoms, medications, the Calama descent plan and what every operator should tell you before a 4 a.m. pickup — all in our altitude sickness guide. For the calendar side (which months are cold at dawn), see when to visit Atacama.