Heat wave killed more than 40 people in the Indian state of Bihar on Saturday.
It came amid an Acute Encephalitis Syndrome outbreak in Muzzafurpur that has killed 80 children this month.
Most heat wave deaths have been reported from Aurangabad, Gaya and Nawada. Twenty seven people died in Aurangabad alone.
Dr Surendra Prasad Singh, a doctor at one of Aurangabad's state-run hospital, said the number of deaths in the district is likely to rise.
He was quoted by NDTV as telling news agency ANI, "Many people were undergoing treatment at different hospitals in the district. All the people who died were suffering from high-temperature fever."
In Gaya, 12 people died due to heat stroke.
Union Health Minister Dr Harsh Vardhan called the deaths in Gaya "unfortunate". "It's very unfortunate that people have died due to heat stroke. I advise people to avoid moving out of house till temperature reduces. Intense heat affects brain and leads to various health issues," he was also quoted by NDTV as telling ANI.
India is witnessing its worst heat wave this year with four of its cities in the north on a record high. Delhi, Churu in Rajasthan and Banda and Allahabad in Uttar Pradesh have witnessed temperatures of 48 degrees Celsius and above.
Heat wave is declared when the temperature remains at 45 degrees Celsius and above for two days running. It gets a "severe" tag when the mercury touches 47 degrees.