A hot dilemma

Should one run early in the morning and get it out of the way (as my students often refer to the pain of attending my classes) or should it be an event to be enjoyed in the evening, when the body has had the whole day to limber up and exercise? It is a tough one for a serious runner. One key variable is the temperature. During the winter in Chicago, it is dark and cold at 6AM and at 6PM, so one could run in the evening (if one prefers) and the weather would not be a factor. Here in Chennai, the temperature is in the mid 80s early in the morning and in the low nineties in the evening- again not much of a difference. One can sweat a lot deciding when to run in this city.