Three fire crews from Thorne and Doncaster stations were called at 11:50pm last night to a house on Parks Road in the Dunscroft area of Doncaster.
All six family members were outside when fire crews arrived. Firefighters wearing breathing apparatus used hose reels to put the fire out.
The kitchen was badly damaged while the rest of the house was smoke logged.
A woman in her twenties was taken to hospital as a precaution.