Dressing properly could help you thrive in any kind of weather. Some runners run hot, others run cool; some sweat a lot, others hardly at all. This is to say that the first order of business is dress for your comfort, not someone elseís
Many runners try to cut their calorie intake as their mileage goes up, only to bonk on their long runs because their body ran out of fuel. The key is eating the correct types of food, and supplying your muscles with enough calories to fuel you through the long run.