This week's bone-chilling temperatures, which dropped to a record-breaking -22 C on Thursday morning, aren't just bad for human bodies. They're bad for transit vehicles, too.

Almost an entire third of Toronto's old streetcars were unable to leave the yard yesterday, according to the TTC, because of – you guessed it – extreme cold weather.

The Globe reports that 45 of the 140 remaining "legacy streetcars" still operating in Toronto broke down yesterday morning, forcing the transit agency to send out buses along the 505 Dundas and 506 Carlton routes.

Extreme cold is taking a toll on #TTC 's 30+-year-old legacy streetcars today. As a result, 505 Dundas and 506 Carlton will be converted to buses today and tomorrow to free up streetcars for busy 501 Queen route. Mechanics working on repairs for next week's service needs. — TTCStuart (@TTCStuart) December 28, 2017

According to the Globe and Mail, the problems appear to stem from issues with the sanding systems and pneumatics that control the doors on older cars, which have long struggled with winter.

At over 30 years old, most of the older streetcars simply aren't equipped to handle this type of sustained cold weather.

TTC spokesperson Stuart Green said that mechanics are working to repair the cars for next week, when ridership is expected to increase post-holidays.

Ops are advised of the cold weather &to do their best to accomodate customers. However if a bus is servicing the stop and if there is a large crowd they will open both doors to speed up boarding. Once customers have boarded a majority do 1/2 ^HK — TTC Customer Service (@TTChelps) December 28, 2017

Of course, none of this would be a problem if Toronto had more new streetcars. The larger, more modern vehicles are faring just fine this winter so far, but Bombardier is way behind on its delivery schedule.

Streetcar issues aside, it's still hard to get around the city during this severe a cold snap.

A GO Transit line was reportedly delayed yesterday after a crack was found in a rail track designed to withstand 60-degree temperature swings, and TTC crews are working hard to keep snow and ice from building up around outdoor power rails.

Fingers crossed these frigid weather systems move along soon – though weather officials say that isn't likely. Extreme cold temperatures are expected to last until at least the end of the first week of 2018.