Generally speaking, we do not keep our thermostat set at any temperature. Due to the MS I suffer from, I find I am hotter in winter and cold in summer. So, we tend to keep the temperature around 60-65.
This is all very strange to me, as I used to love the heat, but now I can no longer tolerate it. I used to hate the cold, but I do not *feel* cold anymore. Most of the time, the colder it is, the hotter I feel. Yes, it is a concern.