Water and salt tablets. Also put a wet towel over your neck to keep you cooler and lose less water through constant sweating.

At the risk of giving away a hidden gem, Aquarius and Pocari Sweat are even better than Gatorade in my experience. Get the powder if you can, especially if you’re making a lot at a time.

You don't have to buy expensive garbage like Gatorade! You can make an electrolyte drink yourself and save money.

• 1 l water
• 0.5 TEAspoons normal salt
• 6 TEAspoons sugar or glucose

Warm everything together while mixing to dissolve the sugar, then allow to cool fully.

You can add some flavor when it has cooled. Lemon, or lime, or artificial flavor if you prefer...

Put it to a bottle, it's ready to go.

Don't give this to small kids without diluting, they cannot handle a lot of salt. For kids (under 1 year), adjust with water, rule of thumb it should taste like at most teardrop level saltiness. Over 1 year can drink as-is. If in doubt, give under one-year olds something from the pharmacy to get the salt amount correct.

Edit: typoed spoons, please check

Liquid IV packets have worked better for me working outdoors doing manual labor than Gatorade, but Gatorade is definitely good too.

I bought a 1 gallon jug recently. I bring it to work every day and it keeps me hydrated for the day. Some of my coworkers only drink one or two bottles of water a day. The workplace has air conditioning, but lacks drinkable water as the tap water in that area is unsafe to drink. The work is also physically demanding, it involves a lot standing, walking, and heavy lifting.

Here.

I'd suggest Gatorade. Hell, I recently read that Gatorade's ingredients are almost exactly the same as what hospitals use to help dehydrated people.

Drink electrolytes (like gatorade) in addition to plenty of water. Do not substitute Gatorade for water. Your body needs electrolytes but only in moderation. Shade will do more for water conservation than you realize. If you stop sweating and you are still hot, stop what you are doing immediately and go drink more water. If you are doing everything right, your piss should be clear or very light in color. If you have dark piss, go drink more water.

@ComradePorkRoll
In 2000, I went to Burning Man, which is, if you don't know, a festival that is held on the dry lake bed in a desert, at the end of summer, at which there is no general provision of water. You are warned when you buy your ticket that your hydration is your problem, and that the average human adult in that environment requires two gallons of potable water a day not to die, so you'd better figure out how long you're going to be there and bring enough water for yourself.

I'd never been camping before under such circumstances, but the person I was attending with had a great bit of advice that worked well for me. He insisted that I get a Camelback, which is a water backpack with a drinking tube.

I made a point of never leaving my tent, not even for a trip to the loo, without having my Camelback on my back. The pragmatic upshot was that drinking water was always as near as my right shoulder. Sipping from the tube became habitual.

I've never been so hydrated in my life.

I try not to sweat

I have an rtic gallon jug that I fill with ice and water everyday. I drink the whole thing during my 10 hour shift. I also drink a Powerade throughout the day. I normally take a sip or two of that and then go for the water.

You know those special evaporate cooling towels?

They're bullshit. Evaporation cooling works, but the sooper speshul microfiber bullshit is no better than a regular thin piece of cloth.