First Night in Aspen: What to Do If You Feel the Altitude
If you’ve just arrived in Aspen and feel a headache coming on, can’t settle, or notice you’re breathing harder than usual, that is a normal response to elevation — and there are four things that will help tonight: stop drinking alcohol, drink more water than you think you need, skip anything strenuous until tomorrow, and consider supplemental oxygen while you sleep.
Most people feel meaningfully better by day two or three. Here’s what’s happening, and when it’s worth calling someone.
Why does the first night feel the worst?
Aspen sits at 7,908 feet. There’s the same 21% oxygen in the air here as at sea level, but there’s less atmospheric pressure pushing it into your bloodstream — so every breath delivers less oxygen than your body is used to.
Your first night compounds several things at once. You’ve likely spent the day traveling, which leaves most people dehydrated before they even arrive. The air in the Roaring Fork Valley is unusually dry, so you’re losing more water through breathing than you would at home. And when you lie down to sleep, your breathing naturally slows — which is exactly when reduced oxygen availability becomes most noticeable.
Many people at altitude also experience periodic breathing during sleep: a cycle where breathing deepens, then briefly pauses, then resumes. It’s common, it’s not dangerous on its own, and it’s a frequent reason people describe their first night as restless even when they were tired enough to sleep well.
This is why the first night is often worse than the flight in, and worse than the following afternoon.
What symptoms are normal at this elevation?
Up to 40% of people who ascend to around 8,000 feet experience some degree of acute mountain sickness. Symptoms typically appear within 6 to 24 hours of arriving, and most people get one or two rather than all of them:
- Headache — the most common symptom and usually the first to show up
- Fatigue or unusual weakness, out of proportion to what you did that day
- Shortness of breath on mild exertion, like carrying a bag upstairs
- Poor appetite or mild nausea
- Lightheadedness
- Trouble sleeping, or unusually vivid dreams
Feeling this way doesn’t mean something has gone wrong. It means your body has noticed the elevation and started adjusting — a process that involves breathing rate, fluid balance, and eventually red blood cell production.
What actually helps tonight?
Stop drinking alcohol. This is the single most effective thing you can do this evening. Alcohol suppresses respiratory drive at exactly the moment your body needs to breathe more, not less. It also disrupts sleep quality, which slows acclimatization. The same applies to sleeping pills and sedatives — avoid both for the first 48 hours.
Drink more water than feels necessary. You are almost certainly more dehydrated than you feel. Dehydration doesn’t cause altitude sickness, but it makes every symptom worse and it’s the easiest variable to fix.
Don’t push through it. Skip the hard hike, the late night, and the big ski day tomorrow morning. Save them for day two or three. Exertion on your first day reliably makes the second day worse.
Take ibuprofen for the headache if you’d normally take it. It’s effective for altitude headache.
Consider oxygen overnight. Supplemental oxygen addresses the underlying cause rather than managing symptoms around it. Many guests find that sleeping on oxygen the first night or two is the difference between waking up recovered and waking up worse. Relief is often noticeable within an hour.
Ask about acetazolamide. Marketed as Diamox, it speeds acclimatization and is most effective started before ascent — but it can still help. It’s a prescription medication and whether it’s appropriate depends on your medical history, so it’s worth an actual conversation rather than borrowing someone’s.
When should you stop waiting and get help?
Most first-night discomfort resolves on its own. A small number of symptoms shouldn’t be waited out.
Seek medical care immediately if you experience:
- Confusion, or trouble thinking clearly
- Difficulty walking straight, or loss of coordination
- Shortness of breath while sitting still, not just on exertion
- A wet cough, or coughing up frothy or pink-tinged fluid
- Lips or fingernails looking blue or gray
These can indicate high-altitude cerebral edema or high-altitude pulmonary edema. Both are uncommon, both are serious, and both worsen quickly without treatment. Call 911 or go to Aspen Valley Hospital at 401 Castle Creek Road. Do not go to sleep on these symptoms.
Descent is the other definitive treatment. Glenwood Springs is about 45 minutes away and roughly 2,000 feet lower, and for someone who is genuinely unwell overnight, it is often a more practical option than waiting until morning.
How long until you feel normal?
Most otherwise healthy people acclimate from the worst symptoms within about four days. Headache, nausea, and breathlessness typically ease substantially over that window.
There’s considerable variation, though — fitness doesn’t predict it, and someone who felt fine on a previous trip can struggle on the next one. Older travelers and anyone with lung or heart conditions often take longer and benefit from having oxygen available for the full stay rather than just the first night.
If you’re on day three and getting worse rather than better, that’s worth a conversation with a clinician.
Need oxygen in Aspen or Snowmass?
Oxygen Now delivers medical-grade oxygen to homes, hotels, and rentals across Aspen and Snowmass, often the same day. We’re physician-owned — founded and led by Dr. Kirk Mahon, a board-certified emergency physician.
Call or text (970) 236-6464
See our oxygen rental equipment · Read the altitude and oxygen FAQ · Learn about altitude sickness symptoms and treatment
Sources: Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness.
This article is for general information and is not a substitute for medical evaluation.
