It looks like their method of making sure the riders inside don't suffer a heat stroke is based on the speed of the gondolas and the air rushing in those large louvres... pretty much like the 60's when you had to rely on the car windows being down and the car moving to survive the trip to grandma's house. Only problem they are going to have is what will happen when the ride stops for an extended period of time... and I there isn't a moving ride at Disney that doesn't have an issue at some point and end up at a dead standstill. I would ride it at night, but no chance I would ever risk riding that thing on a sunny afternoon.