More questions:
Could they get away from the 95 degree area. That is kind of hot unless they can get away from it.
What did you feed them?
Did you or anyone in your family handle them? Keets are not fans of being touched.
As was asked, did they have poop on their butts/rears? Were they pooping?
where were they indoors or in outside shed? Did any other birds have access to them? Did you disinfect the tote before using it?
Did you give them any "treats"?
Did you look at them often? Guineas do best when left alone. really alone.
Do you own waterfowl? Could the waterfowl get close to the keets? Why do you own waterfowl?
Did you buy from an approved hatchery? Someone you knew? A store where 300 people could have touched the birds before you got them?
I cringe when I see birds in a feed store/mill
TSC and so forth, knowing people will buy them and bring them home without knowing who has what disease and has touched them or their feed or the tank. It is like putting a sign out front and asking everyone with a bird disease to walk through your coop and pet your birds.