Thiruvananthapuram: The sun is glaring down on Kerala as the summer gathers steam. Amid scorching heatwave conditions, the first-ever Heat Index Map published by the State Disaster Management Authority has placed Thiruvananthapuram, Kottayam, Alappuzha, Pathanamthitta, and Kozhikode districts under Danger Zone areas.

The classification suggests that chances of suffering lethal sunburn remain much higher in these regions in case of prolonged exposure to sunlight. Certain areas, especially in Thiruvananthapuram and Kozhikode districts, are included in the ‘Extreme Alert’ category, where the sunburn threat is very high. It further states that most parts of the state fall within the 40-45-degree Celsius category, which suggests that prolonged exposure to sunlight will cause fatigue.

Heatstroke is also known as sunburn. It refers to severe heat illness that causes body temperature to go beyond 40.0°C (104.0°F). Red skin, headache, dizziness, and confusion are likely symptoms.

The heat index is prepared by calculating the heat levels, which combine the atmospheric temperature with the humidity. The estimation generally remains a bit higher than the atmospheric temperature levels.

As per the index, most parts of the Idukki and Wayanad districts remain in the 30-40-degree Celsius category while the situation in a handful of villages in Idukki that lie close to the Tamil Nadu border remains relatively better (below 29).

The heat index map has been prepared by compiling the temperature recorded by the Automatic Weather Stations under the India Meteorological Department and the relative humidity levels. The experts, at the same time, also hold the view that the data recorded by the weather stations cannot be regarded as thoroughly scientific.

Heat conditions intensify quickly

The current climatic situation in Kerala is such that the heat index is likely to cross 40-degree Celsius mark even if the atmospheric temperature remains at 36.5-degree Celsius with a humidity level of 40%. If the temperature is 37-degree Celsius with a umidity of 50%, the heat index will go up to 46. This suggests that even a slight increase in atmospheric temperature will worsen the situation.

Meanwhile, Kannur (37.6 degrees Celsius) and Kottayam (37.5 degrees Celsius) recorded the highest temperature levels during the day hours on Thursday.

The IMD has revised its earlier forecast of some districts receiving light rains from March 10 to March 11 onwards.