I live in a tropical climate. My work demands that I am outdoors.
I hydrate and use a recipe similar to @Call_Me_Jay‘s in the post above. Remember that hydration, to be most effective, begins the day before the event to give the fluids enough time to get to muscle and other tissue, including fluid storage spaces between the stria of subdermal fat, which insulates the body from extreme temps and is tapped for sustained hydration throughout your system. Having water in your belly alone is a very small part of hydration.
I am not a mad dog or an Englishman, so I do my work in two shifts; one between dawn
and about 10am, and the other between 4pm and sundown.
I wear light colored clothing that is made of synthetic “gortex” type material that breathes most effectively, wicks sweat away and dries quickly. It is extremely easy to handwash and dries withing 15 minutes indoors. It is so easy that it is impractical and takes longer to wash and dry by machine. In a pinch, I will wear light natural cotton fabrics. Anything else and I feel smothered in this hot, wet environment.
I wear a “boonie” hat (also gortex) and polarized sunglasses whenever I’m outside to protect my head, face and eyes from direct sunlight and UV rays.
I use Zinc cream on certain prominences such as the bridge of my nose and my knees in order to protect against UV damage. Most sunblock will sweat right off, or be washed away the first time I pour water over my head. Sunblocks also block your pores and prevent dermal aspiration—one of the body’s main coolant functions. Blocking skin pores is a recipe for sunstroke.
Throughout the day, I regularly dip my hat in water and dump it over my head. I also throw some on my dogs whether they like it or not. When sailing, I have a bucket on a line attached to a cleat that I regularly throw overboard into the water and then dump it over my head.
Throughout the day I eat watery things like mango, papaya, watermelon and cantaloupe right off the tree or ground.
When overheated, I avoid drinking anything ice cold. It’s not good to do this. Dipping a cloth in iced water and then placing it over your carotids, femoral arteries, on your wrists, under your arms, or behind your knees is a much more effective and safer way to cool down quickly.
Knowing when to quit and head for the shower is probably the most important thing. I also watch my dogs and horse. When they’re looking beat, it’s time to call it quits and go for a swim.