We've had 115 already. Start drinking water well before you go into the heat. You can easily sweat 2 liters/hr but you can only rehydrate at 1.5L/hr. Electrolytes is a totally different issue. Drink one electrolyte drink to every 3-4 waters. Don't risk over heating cuz it has permanent affects. Thanks to my occupation, I now have to drink constantly from the moment I get out of bed and it sucks!
Make sure your AC is in top shape and the coils are clean. Shade, if possible, is paramount. Craig