Almost 6,500 participants of all ages will compete in events for the Community First Fox Cities Marathon this weekend.
But with the potential of extreme heat, organizers have asked runners to take precautions.
Kids' races like the Huggies Diaper Dash and Toddler Trot started Friday night, and organizers were already stressing the importance of hydration.
Temperatures could reach almost 90 degrees Saturday and Sunday. Organizers have added additional resources like water, ice, medical stations and cooling buses along the course.
Doctors have advised runners to drink water or a drink with electrolytes.
"Staying hydrated leading up to the event is paramount," said Dr. Mark Westfall. "Also, drinking additional fluids the day before and avoiding caffeinated beverages and sodas of that nature which lead to dehydration before the event is going to be key as well."
Event organizers said they will not cancel the race because of the heat. There is a flag system in place to let runners know current conditions at the water stations.
That flag system is as follows:
Runners do have the option to participate in the half marathon instead of the full, and will receive a discount for the full marathon in 2018 if the heat or humidity are uncomfortable on race day.
For more information on this year's marathon, visit their website here.
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