Toronto Transit Commission officials are promising a much more comfortable ride for subway commuters as the dog days of summer approach.

TTC officials are looking to avoid a repeat of the summer of 2016, when commuters, already faced with a hotter-than-usual summer, endured sweltering temperatures aboard aging trains with no functioning air conditioning. Passengers were livid to learn that a quarter of the system’s subway cars had no functioning air conditioning.

During a news conference on Tuesday, TTC CEO Andy Byford said officials were “devastated” over the issue last summer.

“We were really aghast at having failed our customers in the way that we did,” he said.

Over the winter and spring the TTC worked to update its HVAC system on some of the older trains on its Bloor-Danforth Line 2. TTC Chair Josh Colle said the fixes will have a “significant impact on the comfortable nature of people’s rides this summer.”

Air conditioning aboard the subway trains frequently broke down in the summer of 2016, leaving many riders sweating and hot under the collar. Toronto Mayor John Tory, who was challenged to ride a hot subway car by an irate passenger in September, acknowledged the transit system needed help, but that old equipment required costly repairs.

Toronto-raised actor Kiefer Sutherland was even snapped enduring a hot ride back in September, when he was in town filming a TV series. A fellow commuter tweeted a photo of Sutherland aboard a subway car. The actor apparently commented aloud, “I’m really hot on this train.”

Byford said Tuesday while there may still be some hot cars, commuters won’t have to deal with the “widespread problems” they experienced last year.