Unite officials have written to contractors urging them to protect tower crane drivers from “greenhouse” cab conditions as the heatwave hits.

The union wants to see extra breaks for crane drivers who often work ten hour shifts with only a single break.

Unite said the vast majority of cranes are not fitted with air conditioning meaning that in hot weather they become glorified “greenhouses”.

High temperatures put crane operators at of suffering heat stress, undermining their ability to concentrate on a job that demands total accuracy at all times.

Unite believes that all tower crane cabs should be fitted with air-conditioning but in the meantime the union is calling for the following minimum standards

• All break times must only start once the operator has reached the site canteen
• No operator to work longer than 3 hours without a break
• A mini fridge/cooler to be placed in all tower crane cabs to ensure the operator has access to cold water
• Bottled drinking water to be supplied free of charge.

Unite national officer for construction Jerry Swain said: “It is imperative that crane operators are fully protected against extreme heat while at work.

“Unite has written to the largest construction contactors seeking assurances that minimum standards are in place to ensure that the health of tower crane operators is being protected.

“If a tower crane operator suffers from heat stress, not only is their own health being put at risk but if they are involved in an accident the entire site could be in danger.

“The long-term solution is for all tower crane cabs to be air conditioned. In the short term, drivers must receive additional breaks, which begin when they reach the canteen, a fridge or cooler is installed in the cab and sufficient quantities of bottled water are freely supplied.”