Ontario's extreme heat is impacting commuters. Here's how

Wednesday, July 13, 2016, 4:40 PM - As hot and humid weather continues in southern Ontario, heat warnings are in place to stress the potential risks of dangerously warm weather.

But for some -- namely, the hundreds of thousands of weekday boarders that use public transit in the GTA -- extreme heat can have an impact even when inside of an air-conditioned train carriage.

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Due to scorching temperatures, Toronto's GO Transit has issued a "slow order," advising commuters that trains will be moving slower than usual on Wednesday -- including the Union Pearson Express.

On hot days that bring plenty of sunshine, railway tracks in direct sunlight can overheat quite easily. Composed of steel, the tracks naturally expand under extreme heat, causing what's known as a "sun kink."

Sun kinks happen heat causes the tracks to push up and buckle, making them wider than normal.

"When it gets hot outside, we constantly inspect and monitor track temperatures. If things get too hot, trains have to slow down over heated tracks, causing delays," GO Transit advised in an animated public service announcement.

The slower a train moves, the lighter the impact is on expanded rails, which in turn lowers the chance of a sun kink.

With humidex values near 40 C expected, the slow order will be in place from 12 p.m. to 8 p.m. Wednesday.

SOURCE: GO Transit | Thumbnail image courtesy of Wikimedia Commons