Ahhh, that's key, too. People who are acclimated to hot weather tend to have less "salty" sweat and therefore need less electrolyte replacement. Well, and you may sweat less for a given amount of work because you're used to it. Working 18 hour shifts, day after day, even a small difference in sweat composition can make a difference over time since even small changes in electrolyte balance can really degrade your performance. Well, the water loss is a much bigger worry than electrolytes.

Actually, that reminds me, we should keep in mind two important yet separate issues when we talk about "What should I drink?" There's the issue of water loss and how to keep hydrated as efficiently as possible. The other issue is electrolyte loss, which really isn't going to kick in for most people until at least several hours of strenuous activity in high temps. In your case, where you are exerting yourself for long periods of time on the fire line, then electrolyte replacemenets becomes a true medical issue to keep in mind.

For many/most of us, electrolyte replacement is rarely needed. We don't sweat enough, for long enough, and then we replenish our electrolytes at the next meal. That said, you can add things to plain water, such as salt and sugar, which will allow your body to absorb the water faster than just plain water. So, the issue can get confusing when asking about the best "electrolyte" drink.