Andy
I usually put my fermenter in a cool place away from the heat and wrap
it with an old water bed heater pad with a thermostat. I put an old
swet shirt around it and stuff a thermometer inside the heater pad and
I can get a rock solid 65 or 70 degrees. Just maske sure the ambient
heat is a little below your desired fermenting temp.

For me the summer is difficult as I have no good way to stay cool other
than AC'ing the whole house. Thats why I prefer brewing in the winter.

Gary
Grants Pass, Oregon