This article was reproduced with the kind permission
of the British Broadcasting Corporation
26 November 2007, 16:59 GMT
Evelyn May Kerr, 84, was found dead by crews who attended a blaze in Yankee Street, Llanberis, Gwynedd on Saturday.
North Wales assistant chief fire officer Paul Claydon said cooking should not be left unattended.
Elsewhere, a man was injured at Port Talbot and in Wrexham a pensioner in sheltered accommodation was found sleeping next to a fire in his flat.
North Wales Fire Service said crews from Llanberis and Caernarfon were called to the property at 1905 GMT on Saturday.
A search of the property was carried out and the body was found.
Mr Claydon said the thoughts of everyone in North Wales Fire and Rescue Service went out to the family of the pensioner.
But he said it was the second time this week that they had been called out to a property where an elderly person had died.
On Wednesday they had attended a house fire in Betws-yn-Rhos, Conwy in which an elderly man had died.
He said:"Yet again, we are urging people not to leave cooking unattended," said Mr Claydon.
"It really only takes a few minutes for smoke to travel throughout your property.
"You should switch everything off on you cooker even if you are only leaving it for a second."
He added the fire service was asking everyone to help them make the homes of the elderly safe by ensure that they have all had a free home fire safety check, and by ensuring the elderly are visited regularly and that there smoke alarms are tested.