A carbon monoxide detector is winning praise from fire officials in Saskatoon, where crews responded Monday morning to an alarm and found "dangerously high" levels of the gas in a home on Cooper Crescent.

Fire officials said the lone human occupant of the the home was already safely outside when crews arrived.

Firefighters checked the home to find CO levels of 503 PPM (parts per million) which they consider “dangerously high”.

The home's natural gas service was turned off and ventilation of home was done.

The firefighters also learned that some pet guinea pigs were still inside and crews donned protective gear to retrieve the animals, which were unharmed.

Officials noted the CO monitor in the home had just recently been installed and its prompt activation may well have saved lives.