Gritters may be a common sight on Hertfordshire’s highways in the winter, but now they’re on standby to ensure the roads are safe in the hot weather too.

A red extreme heat warning has been issued for Wednesday and Thursday this week (June 24 and 25), with temperatures in some areas across the south of England expected to reach 40 °C.

And as the mercury rises, there is a risk that road surfaces in the county could start to soften. The county’s highways chiefs are already monitoring the impact of the weather on the county’s network of roads.

And should the road surfaces start to soften, gritters are on standby to spread grit or sand on the surface, with smaller areas to be dealt with by hand. Commenting on the preparations, a spokesperson for Hertfordshire County Council said: “We have plans in place with our highways contractors to manage the very high temperatures forecast this week.

“Asphalt road surfaces can soften and start to melt in very high temperatures – typically when the surface reaches around 50 °C. This means the impact is usually limited to very exposed sections that get a lot of sun during the day.

“When this happens, localised areas can temporarily become soft and sticky. To counter this, we spread grit or sand on the surface. We have two of our winter gritters on standby to do this if it is necessary, but smaller areas may be done by hand.”

The Met Office has issued a red weather warning for Wednesday and Thursday (June 24 and 25), which covers much of southern and central England (including Hertfordshire) and much of Wales.

At the peak of the heatwave, temperatures are expected to reach at least 39 °C. By Friday, temperatures will be lower, with highs of 32°C forecast across eastern areas.