Heatwave injury preventable, say builders

The heatstroke injury to an apprentice carpenter in Adelaide should have been avoided and all businesses should reconsider their work programs during heatwaves, Master Builders South Australia says.

Travis Mellor, 17, remains in a critical condition in hospital after collapsing from heatstroke on a building site on Wednesday.

He was one of more than 100 presentations to SA hospitals over the past three days for heat-related issues, with that number expected to grow, as the state swelters through a week-long heatwave.

The mercury hit 40.8C in Adelaide on Friday, giving the city its third consecutive day above 40C.

If it reaches its forecast maximum of 43 on Saturday, that will give the city four straight days above 40C for the first time in December.

Master Builders chief executive Ian Markos said the heatstroke suffered by Travis Mellor was avoidable and sends a dire warning to every business.

"We know we are facing a wave of severe heat and, on some building sites, people are working hard in exposed conditions," he said.

"Everyone, regardless of industry, needs to think critically about protecting employees, especially in the wake of this incident."

The CFMEU slammed the apprentice's employer for "utter negligence" for not stopping work in the heat on Wednesday.

"Travis is still a child who had no idea of the danger of toiling in these kinds of conditions," SA branch secretary Aaron Cartledge said.

The Bureau of Meteorology said the heatwave conditions across SA would peak on Saturday with temperatures pushing into the mid-40s in some regional centres.

Acting regional director John Nairn said conditions across South Australia, Victoria, Tasmania and parts of NSW would reach severe on the bureau's heatwave index.

Severe and extreme heatwaves pose significant risk to human health and safety, particularly for the elderly.

But relief is not far away with a milder change to sweep through SA late on Saturday and early on Sunday.

Adelaide is forecast to have a top of just 27C on Sunday.

TRACKING THE TEMPERATURE IN ADELAIDE ON THURSDAY:

*6am: 23.8

*7am: 24.7

*8am: 27.3

*9am: 30.0

*10am: 33.0

*11am: 36.8

*12pm: 39.2

*1pm: 39.2

*1.49pm: 40.8 (max)

*2pm: 39.6

*3pm: 39.7

*4pm: 39.4

Source: Bureau of Meteorology