I think that being comfortably warm is all part of an individual’s own personal preference.
Every once in a while, I will go into a house & wonder just when we need to ask just exactly how warm is too warm.
I think that if it is too hot, it can be dangerous for some people. You are always hearing about the need for the elderly to have fans, if they don’t have a/c, in the summer. When heat waves hit our area, every one of us are being told to check on the elderly. Help the elderly find a safe place where there is a/c or fans. Being a Heating, Ventilation, & A/C specialist, I was in & out of homes where the elderly lived. Some of them favored their temperature controls set at eighty instead of seventy. All of us live in the deep south, & people are shocked to hear that there are still several people who don’t have a/c. When you are born & raised without a/c, it bothers you more when we have the cooler weather than the warmer. They have learned to adapt to the heat by having heavy drapes over the windows to keep out the sun. They have slow-moving fans that keep the air cooler & not just circulate the heat. I get a/c repair calls from the younger people more than from the elderly. I’m not saying that the heat can’t be dangerous for older people, but I get most of my calls for repairs to their heating systems. One elderly person told me that he would rather be too hot than not hot enough.