Firefighters had to rescue a man from his burning bedroom in Nollamara last night.
Fire crews from Osborne Park, Malaga and Perth were called to the Munja Way house about 10pm.
While several other residents managed to escape, a DFES spokesman said firefighters had to push through the flames to rescue the man.
He was suffering severe smoke inhalation and was taken to Sir Charles Gairdner Hospital for treatment.
The fire, which caused about $20,000 damage, is believed to have been deliberately lit.