MEDICAL MATTERS:What to watch out for when the heat is on
THERE HAS been some speculation of late about our prospects for a scorching summer, in particular following the extreme winter we have had. I had been putting my faith in Michael Gallagher, the Donegal postman whose weather predictions since last November have been accurate. But I was disappointed to read that his original prediction of a long hot summer may have been misreported.
However, many of us live in hope, encouraged by a conviction that our childhood summers were warm, lazy affairs, just waiting to be recreated during the next three months. I have been exposed to what I would call uncomfortable heat on two occasions: once on a holiday to the Caribbean and once on a journalistic assignment to Chicago. The humidity of the American midwest was so intense that any forays outside the conference centre were possible only by visiting every fourth shop, regardless of what it sold. I gulped in the cool air while feigning interest in a product, before setting off to the next air-conditioned haven.
The Caribbean experience was a much earlier, and potentially more dangerous, one. With temperatures in the 30s, two weeks of poolside bliss beckoned. Things went swimmingly for about eight days, until one morning my skin felt cool and clammy and I had a bad headache.
Apparently I announced I was bored, expressing a strong desire to go on a ward round – I was a junior doctor at the time. However, it wasn’t until I became convinced the resident lizards were following me around the pool that the penny dropped. I had heat exhaustion and was at risk of developing heat stroke.
Heat exhaustion occurs when people exercise in a hot, humid place and body fluids are lost through sweating, causing the body to overheat. The person’s temperature may be elevated, but not above 40 degrees. Heat stroke develops when the person’s cooling system, which is controlled by the brain, stops working and the internal body temperature rises to the point where damage to the brain or other internal organs may result. The body is usually able to dissipate the heat by either radiation of heat through the skin or by evaporation of sweat. However, in extreme heat, high humidity, or vigorous exertion under the sun, the body may not be able to do this and the person’s temperature rises, sometimes up to 41 degrees or higher.
What are the symptoms of heat exhaustion? The person may look pale, with cool, moist skin. Sweating profusely, they may feel faint or dizzy and complain of muscle cramps. Headache, nausea and thirst are other common symptoms. Treatment involves fluid replacement, rest and the application of wet cloths to the skin. The person with heat stroke may be confused, behave irrationally or develop hallucinations. The skin is dry and the person looks flushed. They may be hyperventilating. Heat stroke can be fatal, with a full-blown case usually needing treatment in a hospital intensive care unit.
Despite the annual warnings about overexposure to the sun causing skin cancer, I suspect many of us regard sunshine as a benign, mood-lifting presence in our lives. A recent survey in the US looked at people’s beliefs about sunlight, tanning and sunscreens. Responding to a statement that “some types of ultraviolet (UV) rays are safe for your skin”, just one-third were aware that it was false and that all forms of UV exposure pose a skin cancer risk. Told that “getting a base tan is a healthy way to protect skin from sun damage”, less than half correctly identified it as a myth. And when asked their views on “using a sunscreen with SPF 30 offers twice the protection of one with SPF 15”, just one in five respondents recognised the statement was false. In fact, an SPF of 30 screens out about 97 per cent of UVB rays, while a factor 15 cream blocks some 93 per cent.
Anyway, back in the Caribbean, after a couple of days’ TLC and some ribbing from fellow holidaymakers, I returned to relative normality. I occasionally wonder what did those innocent lizards make of the demented Irishman chasing them around the pool?