I’m writing this up after coming back a day which while fun for me, did see quite a few people getting gassed out by the heat and activity. I saw a direct correlation between not drinking anything or drinking only soda/energy drinks, and getting ruined by the day’s heat.
Absolutely pack some containers of water to chug down between games, and if you’re in the woods doing extended games, a camelbak or a canteen fitted with a drinking hose is a very good idea to take drinks from during slow times on the field.
The baseline for water intake is roughly 3 liters, per person, per day. That’s a recommendation for everyday life, not running around in the woods, so you should be exceeding it.
If you need a little extra help in getting amped back up or just want some variety from default water, there are plenty of options for electrolyte powders to bring with and put into a bottle. Just knock off the caffeine and sodas until the game time is over.