A red alert implies a “very high chance” of people developing “heat illness and heat stroke” and calls for “extreme care” for vulnerable people, the Indian Meteorological Department said.
India is experiencing unusually high temperatures this summer, and the weather department has said conditions of “heat wave to severe heat wave” are likely to continue in several parts, including the capital, through Wednesday.
India speaks of a heat wave when the maximum temperature of a region is 4.5 C to 6.4 C higher than normal, while a severe heat wave occurs when the maximum temperature is 6.5 C higher than normal or more.
Local weather stations in Delhi's Mungeshpur and Narela districts recorded a temperature of 49.9 degrees Celsius on Tuesday – a record for the city and 9 degrees above normal.
The local government of Delhi also restricted water supply due to the heat. It said water levels in the Yamuna river, its main source, were low.
The city does not have an uninterrupted water supply at any time, but the government said neighborhoods that receive water twice a day for several hours would be subject to further restrictions.
“I appeal to all residents: whether there is a water problem in your area or not, they should handle water very carefully,” the local government's Water Minister Atishi, who used only one name, said on Tuesday.
Billions of people in Asia, including India's neighbor Pakistan, have experienced a hotter summer this year – a trend that international scientists say has been exacerbated by human-induced climate change.
Three more deaths were attributed to heat stroke in Jaipur in Rajasthan state on Tuesday, local media reported, bringing the city's toll to four and the state's to at least 13.
Rising temperatures also prompted India's polling body to take additional measures as Delhi voted in national elections last week, including deploying paramedics to polling stations, which were also equipped with fog machines, shaded waiting areas and cold water dispensers.
The elections end on June 1 and the counting will take place on June 4.