North Queensland health authorities says there has been a spike in the number of people being treated for heat exhaustion.
High temperatures across north Queensland are set to continue for the rest of this week, with humidity levels also climbing.
The Townsville Hospital's Dr Carl O'Cane says people should seek medical help if they have symptoms of heat exhaustion.
"The things you've got to look out for is feeling hot, in particular if you stop sweating, a sign that your body is starting to shut down," he said.
"If you have a rapid pulse, often people get a headache sometimes even dizzy, people who are working with others might notice they are becoming confused."
© ABC 2013
17:37 EDT Much of western New South Wales has begun a heat wave, reaching at least five degrees above average for at least five days, averaging a maximum of 35 degrees or more.