A three-year-old boy was found outside alone early Friday morning, suffering hypothermia, Ottawa paramedics say.

Paramedics say a 911 call came in reporting a boy found walking alone and under-dressed at 4:48 a.m. ET Friday near the east Ottawa intersection of Ogilvie and Blair roads.

The paramedics arrived and treated the boy for mild hypothermia.

A frostbite advisory continues for Friday in Ottawa, and the temperature when the boy was found was colder than -20 C. The windchill also made it feel colder than -30 C.

The boy was taken to hospital in stable condition.

Police said he has since been reunited with his mother, and there won't be any charges laid. The boy managed to unlock the door and leave the house in the middle of the night, they added.