The temperature in the capital Baghdad reportedly approached 52C on Tuesday, one of the highest the city has ever seen.
The heat is said to have remained above 51C on Wednesday.
Many people stayed indoors, with some in central Baghdad seeking respite under an improvised shower.
But the extreme heat has put even greater pressure on the country's already strained public resources.
Electricity cuts have left many people in Baghdad reliant on generators to keep fans and air conditioners running.