At this age they need a brooder just like chicks do. You need to put a heat lamp on them. They could just be chilled. I have had guineas that looked dead come back to life after being warmed up suffeciantly. I had a batch to get sick a month ago and lost several. I gave mine sulfa water and they perked up after a day, or so. These were a bit older then yours and already moved to an outside pen, so we weren't thinking possibly cocci.
Guineas will stay wet if you put a regular chicken waterer in there, which isn't going to help any . You need a quail waterer for young guineas. A small chicken waterer can work, but you have to put marbles, or rocks in the moat so that the guineas can't get too wait, but a quail waterer always works best.