The firm’s Surefit Thermal Safety Helmet Liner is the perfect alternative to hoodies under hard hats which are often banned from site because they interfere with the effectiveness of helmets.

Network Rail and the Track Safety Alliance are the latest organisations to turn to JSP for help.

Steve Featherstone, programme director for Infrastructure Projects – Track said: “The challenge was to develop a thermal safety-hat liner that keeps the wearer’s ears and head warm, allows good hearing and works with a hard hat.”

Darren Bilbie, RMT union area health and safety representative, said: “Feedback from colleagues in the Derby area, who trialled the thermal liners, was very positive.

“All of them stated that they’re what have been needed for a long time to eliminate draughts and cold under and around the helmet.”