Herman said the 6-foot-4, 335-pound sophomore had a "full body cramp" and the team's trainers dunked him in a cold bath to get his body temperature down before an ambulance arrived.
While still hospitalized, Hudson was moved from the ICU after his temperature returned to normal. Hudson will not play Saturday against Tulsa.
"Everything's great,'' Herman said. "His body temperature is back to normal. All the vitals are great.''
Herman said doctors were still running tests to find out why Hudson's body temperature spiked when those of others didn't.
Austin temperatures reached 95 degrees Wednesday afternoon, according to the National Weather Service.
Herman said it was his decision to practice outside instead of using the school's indoor facility.
Texas head athletic trainer for football Anthony Pass explained how Hudson was treated before heading to the hospital.
"Patrick was initially being treated for exertional heat cramps during practice on Wednesday and in the process of treating him, our medical staff identified his body temperature rising," Pass said. "We immediately went into our exertional heat illness protocol, which included cold water immersion in order to get his temperature down and to transport him to the hospital for further care. Patrick remains in the hospital and his condition continues to improve."
Herman said Hudson has had cramping issues in the past.
"He's kind of a cramp guy. For a massive human being, he's not very fleshy. He's got a pretty low percentage of body fat,'' Herman said.
Maryland offensive lineman Jordan McNair died of a heatstroke on June 13 after he was overcome by heat at practice two weeks earlier, prompting the school to part ways with its strength and conditioning coach.
Information from The Associated Press was used in this report.