More death and disease

  • 14/06/1999

During an intense heat wave in July 1995 in Chicago, USA, 726 people died during a four-day period due to heat stress. Heat stress is a condition in which the body is unable to adjust to the external environment because it does not have enough water to cool itself through perspiration. This leads to excessive trapping of heat, resulting in heat stroke. Prolonged bouts of hot weather, especially in cities where concrete tends to trap heat, pose the greatest danger of heat stress, according to World Resources 1998-99 published by The World Resources Institute and others. But the heat wave-related deaths in Orissa in 1998 were spread over urban as well as rural areas.

Especially vulnerable to heat stress are the elderly, the very young and the poor. Cities such as Washington, DC, Shanghai and Athens seem to be at the greatest risk from heat waves as temperature inceases will be higher in temperate countries than tropical ones. It is believed that the normally high average temperatures in tropical and sub-tropical cities help residents adjust to the heat better, so they suffer fewer heat stress problems. But the heat wave-related deaths in India in 1998 defy this logic.

While heat stress is a direct effect of the heat wave, temperature rises associated with global warming will also lead to an increase in the incidence and spread of infectious diseases, especially in tropical countries. For example, the incidence of vector-borne infectious diseases like malaria and kala-azar is expected to rise, as a rise in temperature provides ideal conditions for the disease-causing parasites and the vectors.

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