It's set to be another sleepless night for many people in Melbourne after what is forecast to be a sweltering day.
The Bureau of Meteorology says that Thursday's sweaty city top of 39 may be tempered by a light sea breeze in the afternoon.
But a hot air mass will keep temperatures high into the evening.
The mercury is forecast to remain above 29 degrees on Thursday night and will not dip below that until 7am Friday.
Senior forecaster James Taylor said the temperature would remain in the high 20s for most of Thursday night and the cool change was not expected to arrive until 7am.
The 29-degree maximum on Friday will actually happen before the minimum of 25, he said, and the city temperature during the afternoon is expected to be in the low 20s.
Thursday is a day of total fire ban in the Wimmera, South West, North Central and Central fire districts, which includes Melbourne. Across the rest of the state, the fire danger rating is very high.
The weather bureau has forecast a mild weekend and temperatures next week are likely to be in the high 20s and low 30s.
WorkSafe urged employers to plan how to deal with staff exposed to heat for long periods.
‘‘There are clear safety issues with people working outdoors, but many people who work indoors or in confined spaces are also at risk from indirect heat or fatigue,’’ WorkSafe health and safety operations general manager Lisa Sturzenegger said.
‘‘Some work may have to be rescheduled, or it may have to be modified.’’