Recently moved to the Caribbean and started playing tennis. I'm in my mid 30's in pretty good shape. I can play for hours in the north east, barely break a sweat. When I play for 2 hours in the Caribbean or more I get exhausted playing with the heat index over 100 degrees F. Temperature is usually in the high 80's low 90s and humidity in the 70's during the day. Sunlight is pretty direct with little cloud coverage. I'm drinking water constantly during play and sweating out buckets of water. Any suggestions on how to better cope with the heat and humidity? Thanks!