Gloucestershire Warwickshire Railway has temporarily suspended all train services due to exceptionally high temperatures forecast this week.
The volunteer-led heritage railway says the decision has been made for the safety of passengers, staff and volunteers.
Chairman Professor John Dora said many duties take place outdoors or in areas where temperatures can become much higher than the forecast, including locomotive footplates, platforms and lineside locations.
He also said the railway’s vintage carriages are not air-conditioned and can become very hot.
Affected passengers and group bookings are being contacted directly, with services expected to resume from Saturday.