In May 2022, India and Pakistan saw some of the hottest heat waves in history, with temperatures reaching nearly 50 degrees Celsius (122 degrees Fahrenheit).
People stopped working during the hottest hours of the day and schoolchildren were sent home hours early. Cattle died from heat exhaustion and dehydrated birds fell from the sky.
But 2023 is no joke either. Northern India has seen temperatures of up to 45 degrees Celsius (113 degrees Fahrenheit) in June. Authorities in the states of Bihar and Uttar Pradesh have reported 170 heat-related deaths and hospitals in various Indian regions are reaching capacity.
While temperatures may not climb as high elsewhere, summer has most certainly also arrived in the northern hemisphere ― and with it the risk of heat-related illness. Here's how to stay safe.
Drink water before you get thirsty
The most important thing you can do to stay safe in a heat wave is drink water, said Indian heat expert Abhiyant Tiwari. Drink water regularly, even when you aren't thirsty, says Tiwari. Cool drinks such as water and coconut water are better than hot drinks.
"Don't wait until you get thirsty," Tiwari told DW during the 2022 heat wave. "Thirst during summer is a sign of dehydration. Drink before you get thirsty."
Other experts, such as Catherine Ling, a professor at the Johns Hopkins School of Nursing, say most drinks are fine. Just avoid drinks that contain caffeine which will dehydrate you.
It's also a good idea to avoid alcohol.
Stay indoors if possible
And stay indoors. That's another thing you can do to stay safe in the smoldering heat. And rest during the hottest hours of the day.
"People are trying to keep themselves cool by not going out too often. Many are confined indoors," DW New Delhi correspondent Murali Krishnan said during the record heat wave in May 2022.
But staying inside is not possible for everyone: The heat is hitting laborers hardest, said Krishnan.
"In a country like India, where there are huge swathes of poor people, especially [people working in jobs like] construction, those people have really had to bear the brunt of the heat wave because they have to work. They have to earn money to keep their home fires burning," Krishnan said.
Seek shade and cover your head in the heat
In Pakistan's Jacobabad district, temperatures during the May 2022 heat wave reached 51 degrees Celsius. But agricultural laborers still had to work outdoors. Many got paid per daily shift ― if they didn't show up, they wouldn't make the money needed to survive. Some soaked their clothes in water to make the heat more bearable.
Tiwari advised to wear a head covering if you have to go out or work outdoors. Ling said field workers should also seek shade if possible.
Keep the air moving
Health experts advise older people to stay in air conditioned rooms if they can.
But air conditioning is scarce in India — poor people can't afford the machines and the country faces regular power cuts, which can last up to three hours at a time.
Even when there is air conditioning, says Krishnan, it often fails. Barring the power cuts, the devices break down at a higher rate than normal when it's very hot.
Cooling buildings without air conditioning
Tiwari says Indians in rural areas still use traditional techniques, like placing cow patties on their rooftops, to keep their homes cool. In the cities, meanwhile, some people are installing "cool roofs" that are light in color and absorb less heat than darker roofs.
Radhika Khosla, an associate professor and expert on the future of cooling at the University of Oxford, said you can place pots of water on a roof to encourage evaporative cooling.
You can also try covering your windows to prevent the sun from entering rooms and use fans to keep air circulating. Cold cloths on wrists, the head and neck can also help ward off some of the heat.
El Nino responsible for heat waves?
One reason for the hot temperatures in 2023 so far could be El Nino. The weather phenomenon, which comes about when easterly winds weaken and cease to push warm water from the east into the west Pacific, began emerging in May. During an El Nino phase, warm water is spread across the Pacific, which decreases the ocean's ability to absorb heat trapped around Earth by greenhouse gases.
Even though El Nino is just getting started, its effects can already be felt in India and across the world. Global temperatures in June 2023 so far were almost 1 degree Celsius higher than those recorded in previous Junes. The peak of the phenomenon is expected to hit from November to January. In other words: Even higher temperatures may lie ahead.
Edited by: Zulfikar Abbany and Jane Paulick
Editor's note: This article was originally published on May 18, 2022. It was updated with new heat-related developments in India, as well as information on El Nino, on June 26, 2023.