environment. which will be really tough, brooke. >> lara, stay with me. doctor, so you deal with football players in the dome and elements outside, wherever they're playing for the weekend. we're talking soccer players. these guys are incredibly fit and conditioned, i would have to think. the notion of, though, hallucinating in that kind of . >> it's going to be hot and humid down there. there's no question about that. it'll take its effects on the body and mind. >> what specifically? i hear a lot about cramps. how does the humidity affect that? make that happen? >> we saw a lot of cramps in the last game the u.s. played. several players went down with muscle injuries, anyway. some of that would be cramping, too. as you get dehydrated, the muscles start to spasm up, cramp. that's something you have to watch out for. it's important to stay hydrated to prevent that. >> hydrate, hydrate, hydrate. how much? >> so a lot of water. a lot of water. a lot of gatorade. a lot of sports drinks. you want to get electrolytes along with your water. it's important to start a couple days ahead of time for sure to