The city is considering buying extra heaters to warm up the driver area on Confederation Line trains, Ottawa's director of transit operations says.

An internal OC Transpo update obtained by CBC shows the temperatures in driver cabs on some trains dipped to as low as 7 C and 9 C Thursday morning, when it was -18 C to -22 C outside.

"We are undergoing a period of correction and calibration as we are experiencing operations with full loads and automatic door openings," Troy Charter, the director for transit operations, said in an email to CBC late Thursday.

OC Transpo also had to make adjustments to both the driver cabs and passenger areas to make them more comfortable in the summer heat.

"As part of the corrective review, we are looking at various solutions, including temporary mitigations such as installing temporary auxiliary heaters," wrote Charter.

Several passengers exiting Parliament station Thursday who spoke to CBC were split on whether the public part of the trains were too chilly or just right.

"It was very cold. Every time the door opens, cold wind comes in," Ken Murtagh said, who added he could see his breath on his train.

"It's unbearable sometimes."

For Cooper Jones, who arrived at Parliament about 15 minutes after Murtagh, the temperature on his train was "perfectly fine."

"It was warm. There didn't seem to be any problems with temperature," he said.

The cold is only noticeable when the trains stop at open air stations and the heat escapes, said Jordan Durand.

"I don't know how you prevent that," he said.

Jordan Durand said he only experiences cold on the LRT when the Confederation Line trains stop at open-air stations. (Laura Glowacki/CBC)

Charter noted OC Transpo had to tweak the heating, cooling and ventilation systems on Ottawa's double-decker buses, which had condensation issues when they first started running.

That problem has since been resolved, he said.