High-Altitude Work
At high elevation the air has less oxygen. Workers who go from sea level to a mountain job, mine or high plateau can get altitude sickness within hours, and it can be dangerous. The risk rises above about 8,000 feet but can start lower.
- Mining
- Pipeline & Energy
- Mountain Work
What happens
- Lower air pressure means less oxygen with each breath (hypoxia). Breathing and heart rate rise to compensate.
- Dry air and faster breathing cause dehydration.
- Cold, wind and strong sun are often worse at altitude. See Cold Stress.
Altitude illnesses
- Acute mountain sickness (AMS): headache, nausea, tiredness, dizziness and poor sleep. Common and usually mild.
- High-altitude cerebral edema (HACE): brain swelling with confusion, loss of balance and drowsiness. A medical emergency.
- High-altitude pulmonary edema (HAPE): fluid in the lungs with breathlessness at rest, cough and tight chest. A medical emergency.
Descend and get medical help for confusion, trouble walking, breathlessness at rest or any worsening symptoms. Do not leave someone alone.
Reducing the risk
- Acclimatize: if possible, spend a day or two at a moderate elevation before going higher, and add height gradually. Above about 9,000 feet, many advise increasing sleeping elevation by no more than about 1,000 to 1,600 feet a day.
- Drink plenty of water; avoid alcohol and sedatives, especially in the first days.
- Eat regularly and pace the work. Take extra breaks, particularly on day one.
- Wear sun and cold protection. See Sun Protection.
- Know your health conditions. People with heart or lung disease or sleep apnea should talk to a doctor before working at altitude.
- Ask a doctor about preventive medicine for rapid ascent.
- Supply oxygen and emergency transport for remote sites. See Remote Site Emergencies.
Worksite planning
- Brief workers on altitude symptoms and a buddy system
- Have a plan for descent and evacuation, with a vehicle or helicopter available
- Provide pulse oximeters and first aid with oxygen where the risk is high
- Allow lighter duty for the first days
Standards & references
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