A downright frigid forecast has prompted Toronto’s medical officer of health to issue an extreme cold weather alert for the city.

Environment Canada is calling for a high of -6 C Thursday but the temperature will feel closer -16 this morning when factoring in the wind chill.

Some sunshine may warm things up a tiny bit this afternoon but the temperature is expected to drop to -10 C overnight and will feel like -18 with the wind chill.

Warmer weather isn’t expected to arrive in Toronto until early next week and the alert is in effect until further notice.

When an extreme cold weather alert is issued, the city offers several additional cold-weather related services and adds extra shelter spaces for the homeless.

Two cold weather drop-ins are also open 24 hours a day between Dec. 15 and February 28.

“Those most at risk of cold-related illness are people experiencing homelessness or those underhoused, those who work outdoors, people with a pre-existing heart condition or respiratory illness, the elderly, and infants and young children,” Toronto Public Health said in a news release issued Thursday. “People with heart problems can experience worsening of their condition for several days after cold weather occurs.”

The city has issued the following tips for residents during an extreme cold weather alert:

• Dress in layers, making sure your outer layer is windproof, and cover exposed skin.

• Wear a hat, warm mittens or gloves, and warm boots.

• Stay dry. Your risk of hypothermia is much greater if you are wet.

• Choose wool or synthetic fabrics for your clothes instead of cotton, because cotton stops keeping you warm once it gets wet.

• Seek shelter if you normally spend long periods outside. Depending on the wind chill, exposed skin can freeze in minutes.

• Drink warm fluids, other than alcohol.

• Warm up by taking regular breaks in heated buildings when enjoying winter activities outside.

• Consider rescheduling outdoor activities, or limiting time outdoors, during colder temperatures, especially if it's windy.

• Heat your home to at least 21ºC if infants or elderly people are present.

• Call or visit vulnerable friends, neighbours and family to ensure they are not experiencing any difficulties related to the weather.