Eligibility Details:
Inclusion criteria
- Have a photo identification (ID)
- Male or female individuals age between 18 and 40 years old
- BMI between 19 and 24.9 kg/m2
- Having capacity to consent to the study Exclusion criteria
- Evidence of any physical, mental, and/or medical conditions that would make the
proposed studies relatively more hazardous
- Prior high altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE)
diagnosis
- Born at altitudes greater than 2,100 m (~7,000 ft)
- Systemic disease with or without any functional limitation; including
- controlled hypertension
- controlled diabetes without systemic effects
- Pregnancy determined by urine pregnancy test, detecting presence of human chorionic
gonadotropin (hCG), or less than six weeks postpartum
- Women who are not willing to receive urine pregnancy tests
- Active smoking. Volunteers may be enrolled if they quit smoking for more than 1 year.
- Excess alcohol use: more than ½ L/day of wine consumption or equivalent
- Any current medication use except oral contraceptives.
- Living in areas that are more than 1,200 m (~4,000 feet), or have traveled to areas
that are more than 1,200 m for more than four days within the last 2 months
- Tobacco chewers
- Abnormal hemoglobin or hematocrit levels or presence of hemoglobin S
- Evidence of apnea or other sleeping disorders
- Evidence of asthma
- Lower respiratory infection within the last 30 days
- If applicable, unwilling to refrain from using energy drinks or other caffeinated
beverages for 7 days prior to and during the study
- If applicable, unwilling to refrain from use of all over-the-counter oral medications,
herbal remedies, and nutritional supplements for 7 days prior to and during the study
- Not willing to have blood drawn from an arm vein each test day of the study
- Claustrophobia (inability to wear a facemask) or other active psychiatric conditions
or not willingness to cooperate with the investigators and the other medical team
- Currently enrolled in another research study
- Facial abnormalities that would preclude proper use of a face mask
Pregnancy Prevention/Testing: Women using oral, subdermal or injectable contraceptives, and
those using other means of birth control may participate. A urine pregnancy test will be
conducted as part of the screening process for study participation no more than 7 days
before starting the study. The test result will be read by a female staff member who will
keep the result confidential. If a woman declines to have a pregnancy test, she will not be
able to participate.