Hi pat.
I guess climate could have some bearing on it. Where are you located ?
I think the first thing I'd be doing is checking with a thermometer, to see if there is any temperature increase.
Turn it down for 24-48 hours, allow it to cool for a day or two.
Before turning it back up, take a temperature reading, and check again in a few days to see if there is any temperature increase.
I'd say that should you see an increase, there's not problem with the heating element, but maybe some other issue. ?