Soaring temperatures in Budapest have pushed back the women's 5 000 metres heats from the morning session to the evening session on Wednesday, World Athletics said.
According to AccuWeather, the temperature in the Hungarian capital is expected to reach a high of 32 degrees Celsius on Wednesday.
World Athletics said in a statement that the Wet Bulb Globe Temperature (WBGT) - which is based on a combination of factors including air temperature, humidity, wind direction and cloud cover - will not be at an acceptable level for athletes.
"... so we will be moving the (5 000m) heats to 7pm on Wednesday evening," the governing body said, adding that the heats for the men's and women's 200m races would begin earlier on Wednesday.
Gudaf Tsegay of Ethiopia is the reigning world 5 000m champion. Her bid to retain the title will see her come up against Kenya's Faith Kipyegon - the world record holder in the distance.
