Deaf and hard of hearing people are being urged to ensure they have specialist smoke alarms that can wake them if fire breaks out in their home.
Specialist alarms are being fitted in south Wales at a rate of 24 per week
They use vibrating pads and flashing strobe lights in addition to the loud noise emitted by conventional alarms.
South Wales Fire Service is teaming up with deaf charity RNID to raise awareness and fit alarms.
A third of those with hearing loss would have difficulty waking up to a conventional alarm, say fire chiefs.
This is a particular problem at night because most remove their hearing aids before they go to sleep.
Almost a quarter (23%) say they would even struggle to know if the alarm went off during the day.
Chris Davies of the South Wales Fire Service warned it was likely rented accommodation would only be fitted with standard fire alarms which are entirely unsuitable for deaf or hard of hearing people.
"Contact your local fire station and we will visit your home to give fire safety advice and fit a free smoke alarm that meets your needs," he said.
"Deaf people need to place a vibrating pad under their mattress or pillow at night. If smoke is detected, the alarm will sound and set off the pad to assist in waking them."
Brian Grover of RNID encouraged deaf and hard of hearing people to think about their personal fire safety and ensure they have the right alarm for their needs.
"Fire can strike at anyone's home, but not everyone is equally protected because deaf people cannot rely on hearing an ordinary alarm," he said.
In the South Wales Fire Service's division, specialist alarms are being fitted at a rate of about 24 a week.
The alarms consist of two smoke alarms, a bed/pillow shaker and a strobe light and are free.