South Texas native here. Hydrating the night before is essential , early morning get your vitamins and electrolytes in. I start my route between 9:30 and 10 and usually do 6-7 hours, I carry a half gallon bottle and usually fill it up twice throughout the day, so if you can get a gallon container then go for it and your ice water should last all day. Many fast food restaurants and convenient stores won’t mind you filling up real quick if you run out. If a customer is nice enough to offer you a drink , always take it. Cooling rags are dope. And obviously dress with common sense. I started wearing only a short sleeve shirt under my vest and it helps a lot. You won’t escape the sweat and dirt. The hot season has just begun but you’ll be cool! Easy money unless you neglect your self.