I Live In Florida And Play Tennis And Pickleball 3

I live in Florida and play tennis and pickleball 3 or more hours a day 6 days a week. Also, do a lot of outside yard work. I'm 73 in good health other than high blood pressure. I take Losarton 100 mg and meloxicam 15mg. Lately I seem to be getting a lot of muscle fatigue in neck, shoulder blades, face, jaw and throat after being active in the heat. I do sweat a lot and try to drink plenty of fluids. I'm always thirsty. When I get home after 3 hours of tennis in the hot and humid weather, I have trouble chewing and swallowing. My jaw, facial and throat muscles are weak. Sometimes sore throat. Could this be heat exhaustion?