The City of Toronto issued an extreme cold weather alert Sunday, as Southern Ontario braces for chilly weather conditions.

Toronto's Medical Officer of Health Dr. David McKeown issued the alert Sunday morning. The alert, which triggers extended shelter services for the homeless, is in effect until further notice.

The forecast in Toronto for Sunday calls for a high of -7 C and a low of -13 C, but will feel colder with the wind chill.

During extreme cold weather, residents are encouraged check on family, friends and neighbours who may have difficulties staying warm in the deep freeze. As well, residents are encouraged to dress in layers when headed outdoors.

The people most at risk of cold-related illnesses are those with pre-existing heart conditions or respiratory illness, those taking medications, infants and young children, and the homeless.