Wrong Type of Heat

“Transport officials said rails under direct sunshine might reach 20C (68F) above the surrounding air temperature, causing the steel to expand – raising concern that rails will buckle as temperatures soar.” https://www.telegraph.co.uk/news/2018/06/26/uk-weather-railway-slowdown-stop-tracks-buckling-heatwave-set/

Network Rail assured passengers that slowing trains to mitigate this risk was in no way a consequence of going berserk with the chainsaw in the spring and removing all those miles of shady mature tree cover.