UPDATE: Firefighting crews from nine stations spent this afternoon battling a fire that burnt 30ha of bushland in Perth's western suburbs.
The scrub fire in Jolimont was reported in a triple-0 call at 11.53am and a bushfire advice was issued for residents in surrounding suburbs, a Department of Fire and Emergency Services spokesman said.
The fire started on Selby Street, near Underwood Avenue, and was burning towards the University of WA Research Park.
A spokesman for the university said he had not received any reports of damage to its facilities.
The fire was initially moving quickly in a north-westerly direction and was out of control and unpredictable, but by 2.30pm the DFES said it was moving slowly and was contained but not controlled.
There were hot spots burning in inaccessible bushland at 4pm.
Four helitacs fought the flames with firefighting crews from stations including Claremont, Belmont, Daglish, Kiara and Malaga.
Seventy career Fire and Rescue Service and volunteer Bush Fire Service firefighters from nine stations and brigades braved the extreme weather conditions to tackle the fire.
With the mercury tipped to hit 44C by 3pm, the DFES ensured extra crews were on stand-by amid the catastrophic fire conditions.
The extent of the damage is not yet known.
Firefighters, including aerial, spent the afternoon strengthening containment lines and mopping up.
There were no evacuations from the scene, a DFES spokeswoman said.
"WA Police, St John Ambulance and Western Power are also in attendance," she said.
St John Ambulance took a young girl to Princess Margaret Hospital for Children to be treated for smoke inhalation.
A man was taken to Sir Charles Gairdner Hospital for treatment for smoke inhalation near Challenge Stadium.
The DFES said although there was no threat to lives or homes there was a lot of smoke in the area and people needed to stay alert and monitor their surroundings.
"Although there is no immediate danger, you need to be aware and keep up to date in case the situation changes," the DFES said.
"Watch for signs of a bushfire, especially smoke and flames.
"Close all doors and windows, and turn off evaporative airconditioners, but keep water running through the system, if possible.
"Read through your bushfire survival plan. If you do not have a plan decide what you will do if the situation gets worse."
Motorists were told to avoid the area and to follow the directions of fire and other emergency services personnel.
Roads closed included Selby Street, Underwood Avenue and Brockway Road.
Motorists were urged to be extremely careful when driving through the area.
They were told to turn their car headlights on and drive slowly.
"If you cannot see clearly, pull over, keep your headlights and hazard lights on, and wait until the smoke clears," the DFES said.
"If you have a respiratory condition and you have been affected by smoke you should contact your local doctor or call Health Direct on 1800 022 222."
In the Great Southern, an advice warning was issued for the western part of the Shire of Plantagenet and the northern part of the Shire of Denmark.
Fire crews contained that fire, which started in bushland in Mt Roe National Park.
A Total Fire Ban was declared for Perth, Mandurah, the Perth Hills and surrounding areas, parts of the Goldfields Midlands and the Midwest Gascoyne.
To report behaviour that may breach the Total Fire Ban, which could start a fire, call Crime Stoppers on 1800 333 000.
The DFES warned that during the ban, people must not light fires.
"All open fires for the purpose of cooking or camping are not allowed," the DFES said.
"Hot work such as metal work, grinding, welding, soldering, gas cutting or similar is not allowed unless you have an exemption.
"You must not undertake any other activities that may start a fire."
People who ignore the Total Fire Ban face a fine of up to $25,000 or 12 months jail.
At Perth’s beaches, lifesavers were kept busy with people heading to the ocean to cool off.
Three people were taken to hospital with possible spinal injuries and an 18-year-old woman suffered a fractured wrist at Floreat Beach today.
At Whitfords Beach, a 50-year-old man was given CPR by a surf lifesaver after he was found unconscious in the water by a member of the public.
Surf Lifesaving WA spokesman Cam Dimsey said the man was successfully revived and he had a pulse when he was taken to hospital by St John Ambulance.
Mr Dimsey said the beaches were at their busiest about 10am but there was a lull at noon.
Beaches were expected to get busier again during the hottest part of the day - during the late afternoon.
Mr Dimsey advised beachgoers to be prepared during the hot weather.
“Take extra care when body surfing, stay hydrated and be sun smart,” he said.
The DFES also warned smokers about cigarette disposal.
"A number of small grass and scrub fires have started today through the careless disposal of cigarettes," a spokesperson said.
The DFES wants smokers to properly dispose of cigarettes due to their ability to start bushfires in dangerous fire weather.
During a Total Fire Ban, people who illegally and carelessly dispose of burning tobacco, cigarettes, cigars or a match face a fine of up to $5000.
DFES duty assistant commissioner Gary Gifford said people were threatening community safety by failing to give a second thought to the bushfire risk posed by cigarettes.
"Cigarettes are on fire, so when you toss them away into the bush or mulch while taking a walk or in your car you are effectively holding a match to bushland,” Mr Gifford said.
"No matter what time of the year or weather conditions, always put your cigarette out properly and make sure it is extinguished.
"While it may be the last thing on your mind, small careless actions like flicking your cigarette butt can cause major bushfires."
If you witness smokers disposing of cigarettes illegally, you should take down the vehicle registration, make and model; get a detailed description of the offender; and take down the time and place that the offence was committed.