Organisations and government agencies have urged the public to take care as the mercury is scheduled to peak at 42 degrees today.
The Department of Fire and Emergency Services has issued a total fire ban for Perth and surrounding areas, including Mandurah.
This means any activity which could start a fire is prohibited.
This means you must not light or use any fires in the open air; all open fires for the purpose of cooking or camping are not allowed; and hot work such as metal work, grinding, welding, soldering, gas cutting or similar is not allowed unless you have an exemption.
You could be fined up to $25,000 or jailed for 12 months or both if you ignore the Total Fire Ban.
For information on activities that can or cannot be carried out during a Total Fire Ban visit fes.wa.gov.au/totalfirebans
If the information you want is not available from the website, telephone the Total Fire Ban Information Line on 1800 709 355.
Current Total Fire Bans are also available by visiting www.emergency.wa.gov.au/#totalfirebans.
Serpentine National Park and sections of Pinjarra and Gnangara under Harvest and Vehicle Movement Bans will also be closed today.