The need for a heater is nearly universal; need for a chiller zero in most of the US: exception would be the hottest areas of the country. A fan array on the sump rim can lower tank temperatures about 10 degrees. You want the tank to be a pretty steady 78-80 degrees. 85 is the edge of death from heat; 62 is the edge of death from cold, but since chemical processes including life run faster in heat than in cold, the trip to heat death is (timewise) much faster than that to death by cold.
