Staffordshire Fire and Rescue Service is warning people to take care when heating up wheat bags as hot water bottle substitutes.
The warning comes after two recent incidents involving wheat bags that have caught fire.
The most recent was last Friday afternoon at a property in Ipstones. Firefighters from Cheadle and Ipstones attended the incident on Mayfair Avenue which involved a wheat bag that caught fire while being heated in a microwave.
Firefighters wearing breathing apparatus used one hose reel jet to extinguish the fire, then ventilated the property.
In an earlier incident on March 9 fire crews from Uttoxeter were called to a fire at a house on Lewis Drive in Burton.
The elderly householder had heated a wheat bag in a microwave and then placed it in her bed. But the heat made the bedding catch fire which then spread to the mattress.
Station Manager Mark Wilson said: "We would encourage people to make sure they monitor wheat bags when heating them.
"They shouldn';t be left heating for too long as they can overheat and catch fire as these incidents demonstrate."