There's already been a taste of hot weather and there'll be more days when temperatures soar during summer.
Warragul last week experienced three consecutive days of temperatures exceeding 30 degrees. The peak temperature recorded was 35.1 degrees on Boxing Day.
After a cool start to summer, Ambulance Victoria urged people to treat these soaring temperatures with caution.
A particular message the ambulance service wants people to remember is to "never leave children, older people or pets in parked cars".
Temperatures in cars can double in just minutes, even on a mild day, and can be 20 to 30 degrees hotter inside a car than outside. And, a child's body temperatures rise three to five times faster than an adult.
Almost two-thirds of call-outs Ambulance Victoria received to people locked in cars over the past 12 months were for toddlers aged one to three years. Pakenham was the busiest area in the state for such call-outs.
Heatstroke is a life threatening conditioning which is fatal in up to 80 per cent of cases but is preventable, and those with pre-existing health conditions should take extra care.