Health and safety guidelines for staff visiting high altitude locations
- 1.1 There may be occasions when staff are required to visit / work at a location which is at high altitude (i.e. over 10,000 feet). It is essential to assess an individual's fitness prior to travel, given the possible risks to health that ascent to high altitude may impose.
- 1.2 High altitude medical assessments are necessary for example for staff visiting or working at the JAC telescopes on the summit of Mauna Kea, Hawaii. These guidelines while based on travel to this location are applicable to visits to any other location above 10,000 feet.
- 2.1 Telescopes on the summit of Mauna Kea, sit at an altitude of 13,796 feet (4,200 metres) where the ambient partial pressure of oxygen is only 60% of the sea level value. This affects people in different ways and there are certain dangers which should be clearly understood. For brief visits of a few hours duration there is no significant medical risk for adults in normal good health, although the majority of people do experience some discomfort. The most common symptom is shortness of breath but this is very rarely severe and most people overcome this fairly easily. The next most prominent complaint is headache, which usually develops only after several hours at high altitude; it can be severe.
- Other high altitude complaints, such as lethargy, giddiness, insomnia, etc. affect fewer people (less than 20%). The severity of the symptoms usually increases after several hours at the summit. After 24 hours at high altitude the incidence and severity of symptoms start to diminish.
- 2.2 On rare occasions individuals can exhibit signs of high-altitude pulmonary oedema or high-altitude cerebral oedema; these are potentially fatal conditions and must be treated by taking the affected person back to sea level without delay. The altitude may also aggravate pre-existing cardiovascular and respiratory diseases. One of the problems is that the sufferer may not be fully aware of the seriousness of the situation and it may be necessary for others to decide that retreat to a lower level is necessary.
- 2.3 High altitude facilities such as that on Mauna Kea often employ a mid-level facility, for example the Hale Pohaku Centre on Mauna Kea at an altitude of 9,285 feet (2830m), where visitors en-route to the summit are advised to take a break for at least 30 minutes. Those visiting such locations should ensure they maintain their levels of hydration.
- 2.4 It should be noted that children under sixteen years of age are particularly susceptible to the effects of low oxygen pressure and should not be encouraged to visit. Pregnant women are also at risk at high altitude. In general, any adults with known heart disease, lung disease, high blood pressure or who suffer from frequent severe headaches should not ascend higher than the mid level facility.
3. Rules for STFC staff travelling to high altitude
- 3.1 It is mandatory for STFC staff required to visit or work at a high altitude (in excess of 10,000 feet) to undergo a full medical examination to certificate their fitness to undertake this visit. Examinations will be arranged through Site Occupational Health and/or Safety Advisers and HR sections for which at least six weeks' notice should be given prior to the date of travel. The high altitude fitness medical comprises the following:
- Health and Lifestyle consultation;
- Blood tests, if they have not already been carried out by the General Practitioner;
- Ultrasound of the carotid arteries and abdominal aorta;
- Ultrasound of the heart;
- Vascular screening of the abdominal organs (kidney size, abdominal aorta calibre);
- 12 lead resting ECG;
- 12 lead exercise tolerance test;
- Post screening consultation;
- Lifestyle and/or treatment recommendations; and
- Full written report and follow up consultation if required
- 3.2 A confidential report will be provided to the individual covering the outcome of the examination together with a certificate confirming that the individual is fit to travel to altitude. A copy of this certificate should be passed to the relevant high altitude facility Safety Adviser/HR advisors as proof of fitness
- 3.3 Any member of staff who does not pass the appropriate medical examination will not be allowed to visit or work at a high altitude location.
- 3.4 The fitness of staff to visit and/or work at high altitude should be reviewed and/or re-assessed annually, regardless of age, in case there is an unexpected change in medical status which might affect the risk to the individual. However, frequency of testing will ultimately be at site discretion.
4. Non-STFC staff - visitors and observers
- 4.1 Medical opinion is unequivocal in stating that all visitors to a high altitude location (including short-term visitors of three hours or less and all observers) should also undergo a full assessment by their own GP, who should be familiar with the risks of altitude, before such a visit takes place. As such, all visitors are asked to sign a medical disclaimer stating that they fully understand the risks of ascending to altitude and acknowledging the recommendation to seek medical assurance of fitness prior to travel.
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