KITCHENER -- Fire officials are investigating two fires that broke out in Cambridge on Monday, gutting multiple homes and leaving millions in damage.

The deputy fire chief says it was a difficult day for crews battling the fires, but that they're being investigated separately and are not considered suspicious.

Twenty fire fighters from five stations worked to get the fire on Rouse Avenue under control, as other crew members from Cambridge's sixth station arrived from another fire about 10 minutes away on Linden Drive.

The fire on Rouse spread to two homes and damaged a third, while the other on Linden involved a row of attached homes. Three were damaged by the flames there.

Between the two locations, there was an estimated $2.9 million in damage done.

Two firefighters at the scene on Rouse were overcome by heat exhaustion as temperatures neared 40 degrees Celsius with the humidex.

Both were taken to hospital. One was released on Monday night, while the other remained in hospital on Tuesday afternoon under observation.

Officials say nobody else was injured.

"We are really happy there was not one civilian injury. We did have people that called 911 early, we had working smoke alarms," explains Deputy Fire Chief Brad Churchill.

"Those public education pieces made it a good outcome in the sense that we had two significant events and there was not one civilian injury."

Debbie Gilligan also lost her cat in the fire on Linden Drive.

"They brought him out and he wasn't moving, so we thought he was gone already," she said. "Apparently he made a movement and they took him and got him on oxygen."

Her cat and dog were both saved by firefighters. The pets are now resting at a family member's home.

"There's no injuries, nobody got hurt," Gilligan said. "Property can be replace, the house can be fixed."

Officials are still working to determine the cause of the two fires, but they say they've found the origin of each. They also said they don't believe the fires are suspicious.

Ten people were displaced from their homes in the fire on Linden Drive and the Red Cross is now involved.

Six people were forced from their homes on Rouse Avenue that were seriously damaged in the fire. A third home had damage to its siding and didn't need to be evacuated.

The Red Cross isn't involved with that fire.

The Ontario Fire Marshal has decided not to attend the scene of the fire on Rouse, but will be investigating the Linden Drive fire.