"All trainees are reminded: drink 1/2 to 3/4 canteen per hour, not to exceed 12 canteens per day. You will drink 3 non-caffeinated, non carbonated beverages with each and every meal."
Is what was recited daily when I was in basic training. And yeah, heat stroke is a big issue. I don't think you can blame the instructors really; everyone knows someone that says water tastes bad or whatever. All the instructors know is that everyone better be drinking their water.
Shout-out to all my nexrad tech homies out there 📡