When an unseasonal and potentially deadly heat wave loomed on weather forecasts, this holy month, impact of global warming came home in a brutal way three years ago when a record-breaking heatwave in lower Sindh resulted in around 2,000 fatalities, mainly in Karachi, over the course of a few days.

The temperatures across rising country this week, which rendered major cities into ‘urban heat islands’, are reminiscent of those deadly days in June 2015.

However, there is evidence of increased official preparedness to tackle the weather crisis, particularly in Karachi. In 2015, a June heat wave killed about 1,500 people in Karachi, Pakistan largest city, and leftover 70,000 hospitalized most with heat stroke.

Officials are now working to try to avoid a repeat of that heat disaster a particular challenge as climate change brings ever-hotter years, particularly in already broiling South Asia.

We now keep a closer watch on temperature, air, humidity (and) sunlight parameters of the Bay of Bengal and the Arabian Sea, and register these parameters regularly in the weather charts, which helped predict the October heat wave more accurately and timely, Rashid, of the met office, told the Thomson Reuters Foundation.

Temperatures in the Arabian Sea are showing gradual rising trends for the last six years because of strange weather patterns, which most likely increase the frequency and intensity of cyclones, heat waves, and torrential rains in months in which these were never or rarely seen before, said Rasul, who is also Pakistan permanent representative to the World Meteorological Organization. The city of more than 15 million is hit by frequent power cuts and has few green spaces.

People living on its streets have little access to shelter or safe drinking water, making them acutely at risk in blistering temperatures. The heat wave coincides with the beginning of Ramadan, when millions of devout Pakistanis abstain from food and drink from sunrise to sunset.

Charity says at least 65 people have died in Pakistani city as temperatures exceed 40C But Authorities in Karachi have not confirmed the death toll but urged people to stay indoors and keep drinking water. In 2015, the Edhi morgue ran out of freezer space after about 650 bodies were brought in the space of a few days. Ambulances left decaying corpses outside in the sweltering heat.

Extreme temperatures were also recorded in neighbouring India, with parts of Maharashtra state reaching 47C on Monday. For Pakistan, at ever increasing risk of extreme weather, combating climate change requires action on a war footing. With the latest heatwave in the country setting off alarm bells that a recurrent pattern is setting in, the message could not get any clearer.

Last year, about 222 Indians died because of the heat, the government says, down from 1,111 in 2016 and 2,040 the year before. Temperatures in Karachi are expected to stay above 40C until 24 May, according to weather forecasters. High temperatures were also predicted to last another 48 hours in India.

The experts describe heat wave a symptom of global climate change, aggravated by deforestation and rapid urbanisation. There has been a significant rise in the Earth’s average temperature over the last 100 years due to which we are experiencing such extreme weather conditions both in summers and winters.

The issue of climate change also needs to be included in the curriculum at school and college levels as it will not only help create awareness amongst the youth but also better prepare them to deal with the challenge which is being described as far more horrendous than terrorism.