Toronto police say a child was found outdoors Sunday afternoon clad only in a diaper.

The boy, believed to be about 18 months old, was found in Toronto's west end outside an apartment building.

Police say a passerby got the child out of the cold and put him in her car until officers arrived.

An ambulance was called and the boy was checked over but police say he was not taken to hospital.

Police say the boy was napping, woke up and left his home while his mother was cleaning.

The temperature in Toronto Sunday afternoon was hovering around -9 degrees Celsius.