Council gritters in County Durham and Cumbria have been put on alert because of fears some roads will melt in sweltering conditions.
As the north of England prepares for the hottest weekend of the year so far, gritters may be called on to protect vital road links.
Temperatures are so high bitumen surfaces may soon become viscous and stick to vehicles.
Crushed rock dust is being readied in an effort to protect road surfaces.
A spokesman for Durham County Council said: "We have stopped all surface dressing work throughout the county.
"Our gritter drivers are on stand-by to go out and dust roads should it become necessary.
"Strong sunshine can melt the tar and cause it to bleed through to the surface.
"Left untreated, it can loosen the gravel which is then scrubbed off the road surface.
"Dusting the roads in this way protects the work we have done and makes the road surfaces safer for road users."
Cumbria County Council said some of its fleet of gritters were also being prepared as temperatures were predicted to reach 30C (86F) in some areas over the weekend.