It's my personal dose, so it's wherever I happen to be.
I do move about a bit, so it's not my local environment that is specifically hot, it's my area, and that's about a 20 miles radius around Stratford, UK.
Wherever I am, the readings definitely seem to get higher at night...
I wouldn't be bleating about this if it were not well serious, but you will only REALLY KNOW FOR YOURSELF if you get your OWN COUNTER...
FB!