The fire started in the kitchen of the house in Dalry, North Ayrshire, at about 1.20am yesterday.
A woman, man and teenage boy were taken to Crosshouse hospital in Kilmarnock, East Ayrshire, suffering from smoke inhalation. The woman was given oxygen at the scene.
Two fire service crews from Kilwinning and Dalry took five minutes to extinguish the fire.
A spokeswoman for Strathclyde Fire & Rescue said: "This incident is a stark reminder of fire being a threat to every community in the west of Scotland.
"It is vital that every single home has a working smoke alarm on each level of the property."