Trying to beat the heat almost cost a Mentone family their lives when their evaporative cooling system started a fire in their house.
One of the children noticed smoke filling the house about 1.20am on Friday and woke up her parents.
The smoke was coming from the ducting of the two-storey weatherboard house in Como Parade East.
Smoke alarms activated shortly after the family had woken up.
The Metropolitan Fire Brigade arrived soon after and found the roof space was ablaze and the fire was spreading quickly. The family had evacuated safely.
Commander Marcus Baker said that an aggressive and efficient attack on the fire stopped it spreading through the house.
About 25 firefighters in eight trucks responded to the blaze.
Fire damage was caused to the roof space and the rear of the house, which also has partial water and smoke damage.
MFB fire investigators are at the scene of the fire this morning to confirm the cause of the fire, but it appears to have started in the evaporative cooling system.