content: No. Wikipedia mentioned that it's 160° F. For comparison, hot tubs max out at just slightly above 100° F. It's not uncommon for people to die at Yellow Stone when they don't heed the safety precautions. In addition to the temperatures, I just read that in some places the water is quite acidic and sometimes people fall through thin crust covering very hot water. It's generally safe if you stay on the boardwalk, but I read about one kid accidentally falling off the boardwalk and dying.