The death toll in the heatwave sweeping India has passed 1,000, with temperatures nearing 50C (122F) in some areas.
Most deaths have taken place in the southern states of Telangana and Andhra Pradesh, where at least 1,118 people have died since last week.
Reports say at least 24 people have died from the heat in West Bengal and Orissa.
Temperatures are likely to drop in some parts over the coming days.
Hospitals are on alert to treat heatstroke patients and authorities have advised people to stay indoors.
Heatwave conditions have been prevailing in the two worst-affected southern Indian states since mid-April, but most of the deaths have happened in the past week.
In the worst-hit state of Andhra Pradesh, where temperatures climbed to 47C on Monday, 852 people have died.
"The state government has taken up education programmes through television and other media to tell people not to venture into the outside without a cap, to drink water and other measures," news agency AFP quoted P Tulsi Rani, special commissioner for disaster management in the state, as saying.
"We have also requested NGOs and government organisations to open up drinking water camps so that water will be readily available for all the people in the towns," he added.
In neighbouring Telangana state, 266 people have died in the last week as temperatures hit 48C (118F) over the weekend.
Alfred Innes lives in its capital Hyderabad and says members of the public have received little help so far.
"I have personally witnessed the death of a three-year-old very close to where I stay and that was because of severe heat. It's very sad.
"The government isn't doing much, but as individuals we are trying our best," he added.
Temperatures fell slightly in Telangana on Tuesday, and are expected to start dropping in Andhra Pradesh by the end of the week.
The weather is likely to cool further when the summer monsoon begins at the end of the month.
What is a heatwave?
- Heatwaves are defined as periods of abnormally high temperatures and usually occur between March and June in India
- May is the country's hottest month, with an average maximum temperature of 41C (104F) in Delhi
- Longer, more severe heatwaves are becomingly increasingly frequent globally
- Intense heat can cause cramps, exhaustion and heat stroke
- Thousands of people died across India during heatwaves in 2002 and 2003
- In 2010 around 300 people were killed by intense temperatures, according to media reports from the time
Sources: National Disaster Management Authority of India and BBC
Delhi is enduring a week of sweltering heat as the temperature in the city hit a two-year high of 45.5C (113.9F) on Monday.
The Hindustan Times newspaper carried a front-page photo of a zebra pedestrian crossing in the city melting in the heat.
"It's baking hot out here - our outing has turned into a nightmare," said Meena Sheshadri, a tourist from the western city of Pune, who was visiting a Delhi monument with her children.
"My throat is parched, even though I've been constantly sipping water."
The meteorological department has issued a warning for Orissa, Jharkhand and Andhra Pradesh states saying that maximum temperatures there would remain above 45C (113F).
Meteorological officials said the heatwave was due to a lack of rain.
There are fears that some of the worst-affected states could be hit by drought before the monsoon rains arrive.
The monsoon is expected to hit the southern state of Kerala towards the end of this month before sweeping across the country.