At least 13 people have died and 33 others have been hospitalised with heat-related illnesses in the last 24 hours in Delhi, Safdarjung Hospital said on Thursday.

The hospital said that the city was witnessing a spike in heat-related illnesses. Safdarjung Hospital had reported nine deaths till yesterday. It has also urged all the state health departments to ensure preparedness for timely response in the face of the heatwave.

"Apart from disseminating daily heatwave warnings from the India Meteorological Department, the health ministry also urged officials to ensure the procurement of ORS packs, essential medicines, IV fluids, ice packs, and equipment for managing volume depletion and electrolyte imbalance," it said.

The Delhi Health Ministry has issued an advisory to all the state health departments regarding the preparedness for responding to the heatwave. It has asked the departments to ensure the procurement of oral nutrition supplements, essential medicines, and other essential items.

According to the India Meteorological Department (IMD), the heat wave conditions will start to improve in the coming few days with the arrival of the monsoon and thunderstorm weather in North-West, East, and Central India.

IMD scientist Soma Sen Roy said in a statement, "As the eastern arm of the Southwest monsoon widens, heatwaves will decrease in most parts of the country except Uttar Pradesh."

According to Roy, heavy rainfall is likely to fall in Goa, Karnataka, and Maharashtra over the next three to four days.