I assume you are not talking about wine coolers! Heheh!
Seriously:
A cooler made to directly store drinks (water, Gatoraid, etc.) should be fine if handled the way I described (washed well, etc.) If used, you might want to fill it with municipal tap water and let the water trickle out slowly through the dispenser just to kill off most of the bacteria that might accumulate there. Then refill. If initially in doubt, use diluted bleach in an additional 1st round.
Do note that drinking directly out of the mouth / dispenser of any container will contaminate it with your own bacteria, so you don’t want to start drinking from a container in that way and then come back to it a week later, esp. in warm / hot conditions.
Just common sense stuff, really.
Look, at this point I’m ready for something stronger than wine coolers. :)