Hydration, altitude and dry air: the Salt Lake problem

Salt Lake City sits at 4,226 feet, and in summer its afternoon air is often very dry, so many people here lose more water than they notice. The answer is mostly ordinary: drink steadily through the day, add electrolytes on active days, and learn the signs that you have fallen behind.

The numbers behind the dry feeling

Three figures describe the valley. Salt Lake City is at 4,226 feet and Park City at about 7,000 feet, according to the Utah Office of Tourism. The summit at Park City Mountain reaches 10,026 feet.

Humidity is the third. In long-term averages for 1961 to 1990, Salt Lake City's afternoon relative humidity was about 22% in July and 43% across the year. Winter afternoons run much higher, near 70%. Summer is the dry season here, which is also when most people are outside the longest.

The state's own visitor guidance puts it simply: higher altitude brings less oxygen and lower humidity, increasing your need to urinate while decreasing thirst.

What altitude does to fluid balance

A 1996 review from the Institute of Medicine describes three effects of altitude on the body's water. Low humidity and faster breathing increase water lost through the lungs and skin, though the review notes the size of that effect is not clear. Thirst tends to drop, then returns to normal over a few days. And there is often a short increase in urination lasting, on average, three to four days.

One caution belongs here. Most of that research was done at 3,500 to 4,500 meters, roughly 11,500 to 14,800 feet, well above the valley floor. The direction of the effect is useful. The size of it at 4,226 feet is not well measured, and we will not guess at it.

Mayo Clinic states the practical version: high altitudes can increase dehydration.

Where the valley ends and altitude illness begins

Salt Lake City is not considered high altitude for illness. The CDC says unacclimatized travelers sleeping at 8,000 feet or higher, and sometimes lower, are at risk. Park City sits just below that line. A day on the upper mountain goes above it.

Acute mountain sickness usually begins with a headache, along with loss of appetite, dizziness, fatigue or nausea. The CDC lists dehydration among the conditions clinicians consider when symptoms look like altitude illness, because the two can resemble each other. The same guidance advises avoiding alcohol for the first 48 hours at high altitude.

How to tell you are behind

The NHS lists the common signs of dehydration: thirst, headache, dark yellow and strong-smelling urine, urinating less often than usual, dizziness or light-headedness, tiredness, and a dry mouth, lips and tongue.

Urine color is the simplest check. Mayo Clinic notes that colorless or light yellow urine suggests you are drinking enough.

What helps

Drinking comes first. Mayo Clinic's general guide is about 11.5 to 15.5 cups (2.7 to 3.7 liters) of total fluid a day for healthy adults, with more for exercise, heat and altitude. Your own needs may differ, particularly if a clinician has given you a fluid limit.

A few habits suit this valley:

• Drink before, during and after time on the mountain, and add electrolytes from a sports drink or powder on long days, as Visit Utah suggests.
• Count hot tubs and saunas. Ski Utah notes they speed up dehydration.
• Drink on a schedule for the first few days after arriving, when thirst may be a poor guide.
• For mild dehydration, the NHS advises drinking fluids, and a pharmacist can recommend oral rehydration solutions.

Where IV hydration fits

IV fluids go straight into a vein, so they replace fluid and electrolytes faster than drinking. Cleveland Clinic notes that for someone who is dehydrated, this may support recovery. It also says there is limited scientific evidence of a broader wellness benefit from IV vitamins, and that people seeing a provider for heart disease, high blood pressure, kidney disease or pregnancy should generally avoid IV vitamin therapy.

An IV is a medical service. At RESRV, every first visit begins with intake and a clearance by a licensed nurse practitioner, described on how it works. For those who are cleared, the full menu lists every drip and price.

When to get help

Call 911 or go to an emergency room if someone with signs of dehydration has pale, blue, grey or blotchy skin, lips or tongue, cold skin, difficulty breathing, confusion, or is unusually sleepy or hard to wake. The NHS lists these as possible signs of shock.

At altitude, breathlessness at rest, confusion or poor coordination can signal serious altitude illness. The CDC says descent is urgent in these cases. Get emergency care.

This article is general education, not medical advice. Talk to a qualified clinician about your own health.