Heat Exhaustion article by Doctor Kenneth Prudhoe Club de Mar Medical Centre Palma de Mallorca

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"DOCTOR AT SEA" a monthly Column in The Islander Magazine

Summer hazards in a hot climate

The last few weeks have been extremely hot and even British residents and visitors have melted and adapted to Spanish customs to make life more tolerable. This Englishman has even started blocking out the proverbial mid-day sun with shutters and enjoying every bit of shade and breeze. One of the excellent features of this island are the sea breezes which ameliorate the savage heat of the Spanish summer and presumably is why the Royal Family leave Madrid and come here for August to Marivent ("Sea and wind"). Many non-tourist businesses have been closed for August and the yachties have generally escaped on charter and voyages which has made it a good time for some of to escape north and appreciate the green grass but also the rain of an English summer.

Nevertheless the risk of excessive sun exposure are now well known - the increased risk of skin cancer, the risk of dehydration, heat exhaustion and occasionally heat stroke.

Sun beds have recently been reclassified as certain to cause cancer rather than probably causing cancer and the risks are worse if users start tanning before the age of 30. The risks associated with ultra-violet light from the sun mimics these findings. Melanoma awareness is very high amongst yachties from sunny countries such as Australia and New Zealand but all of us moving into this Mediterranean climate have to behave cautiously after the initial novelty period has passed.

Dehydration is another hazard which can normally be avoided easily by regular fluid intake but sometimes conditions get out of hand - for instance, a hill walk gets extended and water supplies run low - or work is demanding and we forget to drink regularly on a hot day when sweat loss is significant. This type of dehydration is a contributory factor in the onset of heat exhaustion.

On some (much rarer) occasions the temperature control mechanism is overwhelmed and gives up. The body core temperature rapidly increases and sweating stops so the skin becomes dry despite the dramatic overheating. The individual becomes confused, may start to fit, rapidly loses consciousness and death can easily follow (10% mortality). This is heat stroke and it is a medical emergency.

The treatment for heat exhaustion and for heat stroke is the same. The casualty needs to be cooled down by getting them into a shaded area preferably with some air movement. Tepid sponging of their skin will help and also lots of cool drinks. There are proprietary oral rehydration products but a reasonable approximation can be made by adding one tablespoon of salt and five tablespoon of sugar to a litre of orange/blackcurrant juice made up from concentrate.

Rehydration and fluid balance by the oral route is clearly the easiest but sometimes the condition of the patient requires fluid input by other methods such as rectal, subcutaneous via a needle under the skin, or intraosseous into bone via a bone injection gun. These various techniques become crucial in survival situations and are covered in training courses on Medical Care Onboard Ship (previously known as Ship Captain's Medical Course)

Dr Ken Prudhoe, MCA Approved Doctor, can be contacted at Club de Mar Medical Centre, Palma de Mallorca. Tel: (+ 34) 639 949 125.