Firefighters arrived to find found a man and woman in their 20s, and two young children already outside. The man was suffering from burns to his hand and all four were given oxygen after breathing in smoke.
They were all taken to hospital as a precaution.
Two firefighters wearing breathing apparatus entered the flat and extinguished a fire in a bedroom.
It is believed the blaze started after a tumble drier overheated. The room was damaged by fire and smoke.