Meteorologists issued a "red code" heat alert for 12 counties in western Romania for the next two days, with soaring temperatures expected to subside only after sunset.
An "amber code" was issued for the rest of the country, forecasting temperatures up to 39 C (102 F).
The spokesman for the emergency situations department in the eastern city of Galati, Eugen Chirita said a 60-year-old man collapsed in the street and suffered a fatal heart attack brought on by the heat.
The heat wave, which began Monday, is expected to last until the middle of next week.