Vic ambos called to 11 kids in car cases

Children locked in cars during this week's heatwave may as well have a "gun put to their heads", a senior Ambulance Victoria official says.

Paramedics were called to 11 cases of children locked in cars across the state on Monday, as temperatures reached 30C.

Ambulance Victoria operations manager Paul Holman said while some cases were accidental, others appeared to be deliberate.

"I understand at times it's a bit of an inconvenience but it's better to have an inconvenience than a dead child," Mr Holman told reporters on Tuesday.

With Tuesday's 40-plus degrees the start of a four-day heatwave, Mr Holman said ambulance crews will struggle to cope with the influx of heat-related patients despite all available staff being put on duty.

"We will be stretched, there's no two ways about it," Mr Holman said.

"We have recalled all available staff, every available vehicle will be on the road."

Paramedics treated 11 cases of heat exposure on Monday, including a man in his 80s who collapsed while playing lawn bowls.

In the heatwave leading up to Black Saturday in 2009, Ambulance Victoria had a 46 per cent increase in triple-zero calls in three days.

Mr Holman urged Victorians without an emergency condition to seek alternative medical treatment.

"If it is something less urgent then just think about whether a doctor or some other service is more appropriate."