Unofficial reports say 28 people have died of a heatwave in Orissa this April while the government has confirmed four deaths due to sunstroke. The numbers may be contested but it is clear that the heat is creating havoc.

While a heatwave is declared when the temperature is five degrees above normal, the state Met department’s advisory declared a “heatwave” only on one day this month.

The Met release says: “The recorded temperature at stations over Orissa indicate that the rise in temperature is about 2 to 3 degree Celsius above normal except in Angul, Sundergarh and Chandbali where it is about 4 degree Celsius above normal. Based on India Met Department (IMD) criteria, heat wave was realised only on one day, April 18, over North Orissa. Similar temperature trends have also been experienced in previous years.”

The release basically means that there is nothing unusual as far as temperatures go. A heatwave is meant to trigger certain administrative relief measures like an early closure of schools. However, news of deaths (unconfirmed as of now) in Orissa point to the fact that there may be dehydration and severe discomfort even when it is technically not a heatwave.

According to experts, humidity could be an element, especially in the coastal stations of Orissa, that is responsible for this trauma. And the measure that takes this into account is the heat index, still not taken seriously by the Met department.

Experts believe that the concept of heat index would be more helpful in this situation in gauging the “felt temperature” rather than the one captured on the thermometer. The heat index (HI) is an index that combines air temperature and humidity in an attempt to determine the human-perceived equivalent temperature—how hot it feels, termed the “felt air temperature”.

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