The heat of the summer has a bad effect on me

Last year I remember noticing that during the summer I did not feel that great and then again I have felt that way this year. But we have been having very hot weather. We even had 105*F for three days straight. I feel drained and agitated. I was not too sure if it was the heat until we got this cool front and rain that came in. It has been in the 60s the last couple of days. I woke to a really cool house and feel really good this morning. I remember from the past loving the heat (but not the last two years). Do others have issues with the heat as well? And what do you do to help it not affect you so bad. I don't want to spend 3-4 months out of every year feeling all down and agitated.

Kari