When Kapil Dev Nikhanj says the heat is on, it means that the heat is on.

“This is so humid… How can the boys play cricket in such conditions?” Kapil asked Pranab Roy on Thursday, his white T-shirt soaked in sweat.

Kapil was at the Jadavpur University grounds in Salt Lake, wearing the hat of National Cricket Academy (NCA) chairman. He was here to select the 15-member under-19 East Zone squad.

As the youngsters toiled under the sun, Kapil and under-19 coach Pranab Roy sweated it out under the shade.

India’s only World Cup winning captain got a taste of summer swelter on Thursday as heavy incursion of moisture due to a low-pressure trough turned Calcutta into sauna city.

The maximum humidity recorded on Thursday was 94 per cent.

G.C. Debnath, director of the weather section at Regional Meteorological Centre in Alipore, said the “comfort index” stood at 64 degrees around noon, which was 10 degrees above the line.

“The discomfort will continue for the next 48 hours, even if we have some spells of rain in the city,” added Debnath.

A trough of low pressure in the lower atmosphere from Bihar to Gangetic Bengal has caused heavy incursion of moisture in the city and South Bengal districts in the past 48 hours.

“Because of the high moisture content, there is a cloud cover at night. This does not allow the surface heat to escape, pushing up the minimum temperature that is recorded early in the morning,” explained Debnath.

On Thursday morning, the minimum temperature recorded was 28.6 degrees Celsius, two degrees above normal. So, when the sun beat down during the day, the heat and humidity made the city suffer.

Adding to the misery of the rising mercury are cases of heat exhaustion and viral fever. “The rise and fluctuations of temperature are causing viral fevers,” said Subrata Maitra, a critical care expert. “One should have plenty of fluids to fight dehydration and minimise direct exposure to the sun,” he added.

According to the Medical College and Hospital authorities, a few patients with complications related to heat exhaustion have been admitted.

Weakness and lethargy are the common symptoms of heat exhaustion. The signs of heat stroke are high fever, convulsions and low blood pressure.

At BC Roy Memorial Hospital for Children, an average of 30 children are arriving at the outpatients’ department with fever, convulsion and other heat-related disorders every day.

“Some of them are being admitted,” said M.K. Chatterjee, medical superintendent of the hospital.