My mom is in a care home. My mom will be a hundred this December. In the care home they have switched the heating off and in the room where my mom's room is there never gets any sun it was realy cold last. No light I had to put extra blankets on her mom's bed I went to see the nurse in charge who said that the heating had been switched off. I said it's cold to that she replied we won't let your mom get cold but if I hadn't have been there no one would have put a blanket on my mom.
First thing, though - relax. If you hadn't been visiting your mother, I expect the nursing team would have checked up on her anyway - you just got there first :)
Next, get the care home to do something about it. Go online and look up "maximum and minimum thermometer." You can get them for less than $20. Put this in your mother's room, and record the daily temperatures for - say - a week. (Do you visit every day? If not, we'll have to figure out who can do the readings.)
Armed with this information, you can then go to the people in charge and make a formal request that they address the issue. What would you like them to do?
Move her to a non North-facing room;
Provide a safe electric heater and install it properly;
Set up a routine to check that she is warmly dressed and has adequate bed clothes.
Many nursing homes have individual thermostats in each resident's room that automatically regulate the room temperate or have at least some way that the temperature can be controlled in each resident's room. Have you checked the thermostat to see what the temperature is set at? You can request that the thermostat be set at a temperature that is comfortable for your Mom.
When your Mom is in a common area like the dining room, have the staff make sure that she is wearing a long sleeve shirt or sweatshirt or sweater. The elderly have a tendency to get cold anyway. And because they are "just sitting" and are not physically very active, the residents tend to be colder than the nursing staff who feel hot because they are running around taking care of the residents. Many long term care facilities that I worked at had the policy that "the residents control the temperature of the facility rooms and not the staff" so if the rooms were too cold for the residents, then the temperature was increased even if the nursing staff complained that it was too hot and they were sweating.
You know your Mom's needs better than the staff, so if she has used blanket(s) on her bed at home most of her life, then bring blanket(s)or light-weight quilts for your Mom's bed that can be washed frequently in extremely hot water without being ruined. My Mom had a fleece blanket and a light-weight quilt (with cardinals on the fabric) on her bed. The quilt brighten her room and made it more cheerful and homey. She also had a small lap blanket to use when she was in her wheelchair.
Most of us aren't dealing with lack of heat at this time of year, are you from down under Pasport?