Doctors were treating hundreds of victims of heatstroke at hospitals across Pakistan on Thursday after an intense heatwave sent temperatures above normal levels due to climate change, officials said.

Temperatures hit 49C the previous day in Mohenjo Daro. The city, known for its archaeological sites, is in southern Sindh province.

The heatwave is forecast to continue for at least a week.

Authorities have urged people to stay indoors, hydrate and avoid unnecessary travel. But labourers said they did not have a choice because they needed to work to feed their families.

“Pakistan is the fifth most vulnerable country to the impact of climate change. We have witnessed above-normal rains, floods,” Rubina Khursheed Alam, the prime minister’s co-ordinator on climate, said at a news conference in the capital, Islamabad.

Doctors said they had treated hundreds of patients in the eastern city of Lahore, while scores of people were brought to hospitals in Hyderabad, Larkana and Jacobabad districts in the southern Sindh province.

“The situation has been getting worse since yesterday, when people affected by heat started coming to hospitals in the Punjab province,” said Ghulam Farid, a senior health official.

Pakistan has set up emergency response centres at hospitals to treat patients affected by the heat.

The state-run ambulance service is now carrying bottled water and ice to provide emergency treatment to victims of the heat, health officials said.

Heatstroke is a serious illness that occurs when a person’s body temperature rises too quickly, potentially causing some to fall unconscious. Severe heatstroke can cause disability or death.

This year, Pakistan recorded its wettest April since 1961, with more than double the usual monthly rainfall. Last month’s heavy rains killed scores of people, while also destroying property and farmland.

Daytime temperatures are soaring 8C above May’s temperatures, raising fears of flooding in the northwest because of glacial melting.

Monsoon rains and devastating floods in 2022 caused extensive damage in Sindh and Baluchistan provinces, as 1,739 people were killed across the country.

Currently, Pakistan’s southwest and northwestern areas are also experiencing the heatwave.

Authorities have shut schools for a week in Punjab. In the city of Lahore, people were seen swimming in roadside canals.

Pakistan says that despite contributing less than 1% to carbon emissions, it is bearing the brunt of global climate disasters.

Ms Alam said recent erratic changes in weather patterns were the result of man-made climate change.