Mother in law is 97. She lives with us. She is almost always cold even if it's 80 degrees in her room. Constantly telling us to turn up heat. Doesn't believe the temp gauges in her room. Argues and if I put the child lock on she turns it off and then the room can get too cold. What to do?
Let her choose how she wants to live in her own little bubble.
I refused to be hot in my own home(as I am more hot natured), so my husband would wear hoodie sweatshirts and flannel pj pants or sweatpants year round. And when he became bedridden in our living room, I would also just put an extra blanket on him if he complained of being cold.
So I would just have your MIL bundle up in many layers around the house so you all don't have to be dyeing of heat stroke in your own home.
The question here is WHY is this happening. In my partner's case it is that he is very very slender. Almost no body fat. And he is cold almost all the time. Long underwear (silk or lightweight wool blends) works, but he is often in a lightweight quilted vest or jacket when I am broiling with the heat at 70. He DID check out if there is a reason, and that's what I will suggest with you. Check for things such as thyroid function, and etc. Speak with your Mom's doc. There may be no choice but to put on a knit hat indoors, ultimately, but you DO need to know there is not a medical reason causing this.