Surviving in extreme cold

I watched a TED video today of a talk by Ken Kamler. He was a medic on an expedition to Everest where the climbers were caught out by extreme conditions nearing the summit. Several were killed. Last week on our BOHS Module courseM201 "Thermal Environment and Non-ionising Radiation" we discussed the effects of exposure to cold conditions. This video provides some dramatic illustrations.

One of the climbers caught out on the summit survived unexpectedly. An example of where willpower can lead to someone triumphing against extreme adversity. In his talk, Ken Kamler provides a physiological explanation for this.

Girls Aloud on occupational health?

I wouldn't admit to being a fan of Girls Aloud - I'm not sure what it would do to my reputation of I did! However, it was good to see the article in the Observer today about the campaign by Nicola Roberts, the red headed, pales skinned member of the group, against the use of sunbeds by under 18s. She features in a documentary - "Nicola Roberts – The Truth About Tanning", on BBC3 on Thursday 4th February.

Excessive exposure to UV radiation can lead to a number of skin problems including malignant melanoma. Young people are particularly vulnerable. According to the International Agency for Research on Cancer, the risk of melanoma was increased by 75% in people who started using sunbeds regularly before the age of 30. Yet peer pressure forces many pales skinned young people to use sun beds to try to give themselves a fashionable tan.

We cover the risks of non-ionising radiation on BOHS module M201 "Thermal Environment and Non-ionising radiation" which we are running w/c 22 March. I can't promise that Girls Aloud will be performing though!

Photo credit: Flickr http://www.flickr.com/photos/22948324@N08/2520077527/

Hypothermia

Working outdoors in Alaska

A recent posting on the Catlin Arctic survey blog discusses the effects of working in temperatures of below -40 degrees centigrade.

Hypothermia is the result of general cooling of the body below 35 degrees C. Early symptoms include tiredness, muscular weakness and confusion. Below 30 to 32 degrees shivering stops and unconsciousness can occur. When shivering stops there is a rapid decrease of body temperature. Death may occur at where the core temperature is around or below 28 degrees C.

The body produces heat and the harder you are working the more heat is generated. At low temperatures we are likely to lose heat to the environment, the extent of this heat loss, however, will be influenced by the amount and type of clothing being worn. Chemical protective clothing can present a particular problem. Even in cold environments it is possible to suffer heat stress and strain where heavy work is being undertaken and impervious clothing is worn which does not allow enough of the heat produced to escape. This is particularly relevant to chemical workers and emergency response personnel.

The Catlin team are pulling heavy sledges of 110 kilos each an average of 6 nautical miles a day. Their clothing is of a high standard in terms of the insulation it provides, but insulation alone is not enough to prevent hypothermia in such extreme conditions as they are experiencing. as the team Doctor notes

“All clothing can do is slow down the process of losing heat. “The only way they can keep the hypothermia at bay is to keep moving and to keep eating”.

Life at the Extremes

I was running the BOHS module on Thermal environment, non-ionising radiation and lighting last week. That's one hell of a course to teach. So many topics to cover and most of the attendees hadn't much experience of them.

For anyone wanting to know more about heat and cold stress, this book by Frances Ashcroft is a nice gentle introduction. It is very well written, easy to read and explains the basic principles very well with some good real life examples.

As well as heat and cold, it covers other challenging environments that might be of interest to occupational hygienists and physicians - high altitude and hyperbaric (high pressure).