Nats Park on a 95+ day may be no fun, but one's real heat endurance was tested severely at RFK - especially back during the first season when the stewards took everyone's water off them until the DC health authorities called them off - until then the only way to get water was to waste an inning (or more) on a food queue. But water or no water, the place was a sauna - as Casey Stengel said of old Busch Stadium when it hosted the ASG in 1966: 'It holds the heat well' (now the concourses did provide some cross-ventilation at times but one could not see the match from many areas thereon).
The worst seats in RFK on really hot days were in the mezzanine section. You might catch the occasional light breeze in the upper deck, but there was no air circulation in the mezzanine at all.
