Ontario’s heat wave has put some Metrolinx operations on ice.

It announced Tuesday that its GO trains will be running at slower speeds while the heat warning persists.

“During prolonged periods of high heat, rail tracks have the potential to soften and expand that require us to run trains at slower speeds. To ensure the safety of our customers and crew, slow orders are issued along the network which also reduce the risk of track damage,” said a Metrolinx advisory.