The 40-year-old man from Bihar's Darbhanga died at Ram Manohar Lohia hospital on Wednesday.
He was admitted to the hospital late Monday night.
This is the first death due to heat stroke reported in Delhi this year.
Reportedly, the man was kept in a room without any fan or cooler while his temperature was high at 107 degree Celsius.
The Mungeshpur weather station on Wednesday reported a temperature was as high as 52.3 degree Celsius, the highest in the country.
In an IMD bulletin, it was reported that the temperature in Mungeshpur was 52.9 degree Celsius.
However, the weather office is investigating whether temperature recording was correct or a sensor error.
"It looks abnormal as it is an outlier compared with all other stations in NCR. We have issued a press release now. A team has also been sent to check the data at the spot (sic)," DG IMD said as quoted by India Today.
With the soaring temperature, the demand for power supplies rose to the peak on Wednesday.