Prolonged Hypoxic Breathing in Healthy Volunteers: a Safety Study

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 c…