Karachi heat index reaches 54°C as humid conditions intensify

KARACHI: Karachi’s heat index climbed to 54°C on Wednesday afternoon even though the city’s maximum recorded temperature was 37.4°C, according to Met Office data, as humid conditions sharply increased the intensity of the heat.

The data showed the feels-like temperature rose steadily from 49°C at around 1pm to 54°C by 3pm. Relative humidity was recorded at 79 per cent in the morning and 65pc in the evening, while the minimum temperature in the city was 30°C.

Sindh districts record higher temperatures

Several other parts of Sindh saw even hotter conditions in terms of actual temperature. Jacobabad was the hottest location in the province at 49.5°C, followed by Dadu at 49°C. Paddidan and Sukkur recorded 47°C each, while Mohenjo Daro, Larkana and Shaheed Benazirabad registered 46.5°C. Rohri recorded 46°C, Khairpur 45.5°C and Sakrand 45°C.

Chief Meteorologist Ameer Hyder Laghari said the prevailing high-pressure area over the region was expected to weaken after Friday, bringing some respite in temperatures. “We are expecting relief after Friday (tomorrow). The high pressure area developed over the region will gradually subside and the temperature will drop to 36°C to 34°C. But, there are no chances of rain in coming days in Karachi,” he stated.

He also said Karachi’s highest temperature ever recorded in June was 47°C on June 18, 1979.

Doctors advise precautions against heat illness

Dr Nadeemullah Khan, Professor and Chair of the Department of Emergency Medicine at Aga Khan University Hospital, said maintaining hydration remained the most important step in preventing heat-related illness. “Avoid sugary drinks, caffeinated beverages, tea, coffee and alcohol, which accelerate fluid loss. Avoid the hottest hours and use air conditioning or cooling spaces, if possible. Evidence shows that time in air-conditioned environments is among the strongest protective factors against heat death. Fans alone are insufficient when ambient temperature exceeds body temperature,” he advised.

He said heavy protective gear and dark clothing increased heat absorption, and added that women whose cultural dress limited heat dissipation faced greater risk and should take extra precautions. He also said workers should be provided water, shade and rest breaks, while new workers and those returning from leave should be allowed time to acclimatise gradually. According to him, elderly or other high-risk workers should not be assigned heavy labour during periods of extreme heat.

Dr Khan said children and older people were the two groups most vulnerable during severe heat. He explained that children absorb environmental heat faster than adults because of a higher surface area-to-body mass ratio, while their sweating response is slower and less effective in releasing heat. “Children have a higher surface area-to-body mass ratio, meaning they absorb heat from the environment faster than adults. Their sweat rates are slower, they have a higher temperature threshold before sweating begins, and they produce more dilute sweat, all of which impair heat dissipation,” he added.

He stressed that children should never be left inside parked vehicles because temperatures inside can become fatal within minutes, and said outdoor play and sports should be limited to early morning or evening with frequent water breaks.

On the risks faced by the elderly, Dr Khan said reduced cardiovascular reserve made it harder for them to raise heart rate and redirect blood flow to the skin for cooling.

“Their reduced mobility, immobility and loss of heat-shock proteins increase vulnerability. Many elderly patients live alone, in poorly ventilated homes, without electricity or air conditioning, a critically dangerous combination during heat waves,' he warned.

He said community health workers and family members should carry out twice-daily welfare checks on elderly people during extreme heat events.