Hot temperatures are rare at the end of summer. However, even in cooler weather, it is important to remain vigilant about your level of hydration when practicing endurance sports. 
Moreover, when we talk about endurance sports, we often immediately think of dehydration. However, a large part of the discomfort observed during long distance runs is actually due to overhydration! 
Drinking too much water during a run (overhydration) can lead to what is called hyponatremia, which is a decrease in the amount of sodium in the blood. This pathology can lead to discomfort, confusion, nausea and vomiting, and in extreme cases can lead to a coma. To avoid these symptoms, it is strongly recommended to drink only when you are thirsty, and not to prevent thirst. In the case of hyponatremia, it is important to avoid liquid ingestion and to consume salt. 
A problem that is frequently encountered with the practice of endurance sports, especially in summer, is a heat stroke. This is an increase in body temperature that can lead to symptoms similar to hyponatremia. To help prevent heat stroke, make sure to cool down when you are very hot. Of course, drinking can be important (if you feel thirsty), but using water to splash your head and body during activity is a much more effective way to lower body temperature. 
So, in summary, when practicing endurance sports, we drink when we are thirsty and we splash water when we are hot! 
What other problems do you think you have to be alert of during a long distance race?