Grand Slam tournaments are getting hotter, and US Open players and fans are feeling that this week

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NEW YORK (AP) — Andy Murray prepared for the steamy conditions often found at the US Open by simulating the “brutal heat and humidity” in New York this time of year with the help of, well, an actual steam room at his home.

The 36-year-old British tennis star set the humidity in there at 70% and spent hours riding a stationary bike nearby with the thermostat cranked up to 95 degrees Fahrenheit (35 Celsius), making the air feel as muggy as it does every summer around Flushing Meadows, where the year’s last Grand Slam tournament will conclude Sunday. "Just to try and help with the heat adaptation," explained Murray, who claimed the title in New York in 2012 but lost in mild conditions in the second round this time.

If the start of competition at the 2023 US Open offered a bit of a reprieve for athletes, ball crews and spectators alike, thanks to highs mostly in the 70s F (20s C), that has decidedly changed. The temperature hit 90 F (32 C) on Sunday and again Tuesday, leaving players seeking relief from ice stuffed in plastic bags or cold air blown through tubes on the sideline. Tournament officials altered the rules and partially shut the Arthur Ashe Stadium roof to offer extra shade. The high was expected to reach 95 F (35 C) on Wednesday.

That's not a surprise: An Associated Press analysis shows the average high temperatures felt during the US Open and the three other major tennis tournaments steadily have gotten higher and more dangerous in recent decades, reflecting the climate change that created record heat waves around the globe this summer. For athletes, it can keep them from playing their best and, worse, increases the likelihood of heat-related illness.

"It was super hot tonight. Really muggy. Super humid,"

Frances Tiafoe said after losing to fellow American Ben Shelton in the quarterfinals Tuesday night, when the humidity climbed to 70%. "Was sweating a lot."