Lifelong central Floridian here! The heat and humidity are brutal in the summer. We start early, go slowly, and keep hikes, bike rides, etc. short - a five mile hike is plenty in the summer. For hydration, I freeze my water bottles the night before a hike so I have cold water to drink throughout and also to ensure I don’t chug down too much water at once, which has made me sick from over hydration in the past. And when it’s just too miserable to get out, we head to the YMCA pool!