Lichfield train passengers are being warned that the hot weather could cause delays.
A spokesperson said: “Summer is definitely here and on hot days, rails can expand as they heat.
“While measures are taken when they are installed to enable them to expand safely in extreme conditions rails can buckle. If this was to happen we cannot run trains through the area and repairs cannot be made until the temperature of the rail has dropped.
“As a precaution and to help prevent rails from buckling we may put speed restrictions on trains through the area at risk, to help keep the pressure on the rail low and keep you safe.
“This may mean some journeys may take longer than usual.”