This article was reproduced with the kind permission
of the British Broadcasting Corporation
13 November 2007, 13:59 GMT
It is thought fairy lights caused clothing to ignite at a house in Saltney Ferry, Deeside, on Monday.
The family were alerted by the smell of smoke and the children's father, who was treated for smoke inhalation, used water to put out the fire.
Fire chiefs said lights should be "thoroughly checked" for defects.
North Wales Fire and Rescue Service spokesman Richie Everall added: "Lights should be thoroughly checked for defects and broken wiring, and flammable items should not be placed on top or too near to the bulbs.
"The last person to retire to bed should switch off all lights and when leaving the house, all lights should be extinguished."
Mr Everall also highlighted the importance of fitting and checking smoke detectors.
People in north Wales can call 0800 169 1234 or e-mail firstname.lastname@example.org for a free home fire safety check.