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
13:25 EDT After a fairly cloudy morning, Sydney's skies are clearing nicely for a starry but cool night for Carols at the Domain.