Thanks to everyone who dropped a suggestion! We just closed the show, and no one passed out thank god! Which was kind of surprising, during the opening show's intermission, the TD walked up to me and told me that it was 81 degrees in the house! We sold 12 cases of water the first night, and left out coolers of ice for the actors backstage.
For Ren, we set up a station on stage left with a gallon container of water, and a gallon container of Gatorade, as well as towels for drying off (the sweat was literally pouring of of him) and one of those spritzy fans that's a fan and a water spray container. It was definitely a long show, but we got through it!