Prolonged sun exposure and heavy work increase the risk of heat cramps or heat rash. Vulnerable people like infants, the elderly, and those with chronic diseases are at high risk in all other districts, it said.

Meanwhile, the IMD issued an orange alert (be prepared) in Kolkata for a heatwave that is expected to persist until Wednesday. An orange alert has also been issued for North 24 Parganas, South 24 Parganas, Howrah, Hooghly, Purulia, Murshidabad, and Nadia.

On Saturday, Kolkata experienced a high temperature of 40 degrees Celsius and a maximum humidity of 89 per cent. The sky was clear throughout the day, and there was no chance of rainfall.

The weather agency forecast a gradual rise in daytime temperatures by 1-2 degrees Celsius over the next three days in West Bengal, with no significant changes expected for the following two days.

On Saturday, the highest maximum temperature was recorded in Kalaikunda at 44.7 degrees Celsius, followed by Panagarh at 44.6 degrees Celsius, Bankura at 44 degrees Celsius, Burdwan at 42.6 degrees Celsius, and Barrackpore at 42 degrees Celsius. The maximum temperature in D amond Harbour, Midnapore, Canning, Krishnanagar, Birdhwan, Jhargram, Purulia, and Asansol remained at around 42 degrees Celsius.

Darjeeling and Kalimpong are experiencing light to moderate rainfall accompanied by thunder which is expected to continue until next Tuesday. Meanwhile, due to hot and humid weather, northern districts such as Jalpaiguri and Alipurduar have been issued a yellow warning. In addition, North Dinajpur, South Dinajpur, and Malda have been issued an orange alert for heatwave conditions which are expected to continue until Wednesday.

The maximum temperatures recorded on Friday were 23 degrees Celsius in Darjeeling, 26 degrees Celsius in Kalimpong, 36 degrees Celsius in Jalpaiguri and Alipurduar, 36.5 degrees Celsius in Cooch Behar, and 42.4 degrees Celsius in Malda.