Excessive climatic heat

There are regions, including many in developing countries, where high ambient temperatures combined with high humidity of the air and intensive solar radiation make it difficult for the human body to get rid of its surplus heat. The physiological rhythm of work, fatigue and recovery is disturbed by high body temperatures. Fatigue accumulates and efficiency in the performance of mental and physical tasks declines. Neither acclimatization nor adaptation can completely overcome the disadvantages of an unfavourable climate. Continuous exposure to heat for many hours may result in heatstroke.

A heat wave in 1998 in the USA claimed many lives. In New York alone the death toll reached 120 people, in Dallas 17 days of extreme heat resulted in at least 23 deaths. The heat itself was not the only danger. Cooler air further north mixed with the hot air from the south to produce violent storms which caused flooding and disruptions in power supplies, which in turn resulted in more deaths.

Also in 1998 a heat wave in Eastern Europe claimed 20 lives in Romania and 52 in Cyprus. Most of the people who died were over 70.

Unusually extreme heat affects all ecosystems. High water temperatures in the Caribbean and adjacent waters has caused coral animals to loose the brown algae than normally live inside their cells in a symbiotic relationship. If the temperatures continue to be high the survival of coral in the Caribbean could be threatened.