Police are investigating a deliberate attempt to set an Oswestry home on fire while four people were inside.
A senior detective appealed for information to help identify the arsonists following the incident at a house in Maple Court shortly after 1am today.
Shropshire Fire and Rescue Service notified the police at 1.18am they were attending the fire.
Two adults - a man and a woman - and two children aged three and a three-month-old baby, escaped without injury.
The woman suffered from the effects of smoke inhalation and was given oxygen to help her recover.
Damage to the property was superficial, with scorch marks on the inside of the door and immediate surrounds. There was also smoke damage to the premises.
Detective Inspector Mick Homden said: "This was a deliberate attempt to set the house on fire. It appears a substance was put through the letterbox and set alight.
"Fortunately, the two adults and two very young children were able to get out without serious mishap. But it could have resulted in a tragedy and the incident is being treated as arson with intent to endanger life."
He appealed for public help in tracing the offenders. "I urge anyone with information which may help the police, to call Oswestry CID on 0300 333 3000. This is a serious crime and we are anxious to identify those responsible.
"If you saw anyone or possibly a group of people acting suspiciously in the Maple Court area around 12.30am to 2am, please contact the police. And if you think you might know the identities of those involved, please call."
Information can also be given to the anonymous Crimestoppers number, 0800 555 111, for which a reward may be paid."