Editor's note: Marine geophysicist Robin Bell is leading an expedition to Antarctica to explore a mysterious mountain range beneath the ice sheet. Following is the thirteenth of her updates on the effort as part of ScientificAmerican.com's in-depth report on the "Future of the Poles."

McMURDO STATION, ANTARTICA-- We are all strapped into our seats preparing for our last ride to the Willy Ice Runway when I have a momentary panic. I did not take my drugs after dinner.  I had been fixated on some last minute details, like getting the case filled with tubing and regulators for the pilots and finding one tardy team member. As far as I could remember the small zip lock back was in my mid-thigh pocket.  Normally this would not be a problem to reach, but right now I am wearing the required gear for flying on a ski equipped Air National Guard C-130 aircraft.  Reaching that pocket through the overall windpants and the big heavy down jacket,  and around the sea belt seemed hopeless. 

When I mentioned my quandary to my companions several bags of the small white pills instantly appeared. We all chuckle at what a strange situation it is to be sharing drugs provided by the government. However, we are heading to high altitude in our flight to South Pole and the small white pills are diamox, part of the strict protocol for acclimatization.  It is no joke.  Our last high altitude East Antarctica science program resulted in seven medical evacuations from the camp. One woman had serious acute cerebral edema.  Everyone on the team has heard the stories as they are the core of the high altitude class we took at McMurdo Station.  Even the pilots are leaning toward adjusting slowly to the altitude.

The underlying source of the problem with humans at high altitude is that there is less oxygen in each breath you take.  The normal response to high altitude is to be short of breath even without any exercise, to feel really tired, to have trouble sleeping, to urinate excessively and to loose your appetite.  If things go well, these symptoms will go away in 24 hours or so.  If things don’t go well, one can get acute mountain sickness, which often starts with a headache reminiscent of a hangover.  If things get worse, the mountain sickness can impact either your brain or lungs. In the pulmonary version, the lungs fill with water.  The frothy bloody cough associated with high altitude pulmonary edema was probably the symptom recorded by the Chinese over a thousand years ago. 

The cerebral version starts with a really, really bad headache and loss of coordination. Fluid is leaking in the brain cavity putting pressure on the nervous system.  These are serious  complications and would render us unable to function normally, much less complete our science.

Mountaineers encounter these problems all the time.  They have developed the strategy of climb high and sleep low.  Our work requires us to travel to the camps by air to have any chance of completing the work in the time allotted.  We will spend a week of precious time on the ice acclimatizing.  In camp, we will watch one another carefully for any sign of symptoms.  The camp medic will check the oxygen saturation levels of our blood several times a day. If things get really bad, the camp has several Gamov bags (pictured, above and left) that can be used to simulate a lower elevation. 

The bags are like an airtight body bag with a window. Once a person is in a Gamov bag, we would have to call for a plane to take  him or her out to a lower elevation. I hope we don’t reach the point where we have to use one.  We continue to balance being proactive about getting the science done and making sure people are safe.  Right now we are starting our long weekend at the South Pole as our bodies adjust to the altitude.

(Photos courtesy Robin Bell)