Hearts fluttered when it was reported yesterday afternoon that Joe Paterno had been taken by ambulance to Mount Nittany Medical Center in the late morning complaining of nausea, weakness and fatigue.

But after being treated for dehydration and undergoing several hours of tests, the 81-year-old Penn State football coach was released by late afternoon, said Jeff Nelson, assistant athletic director for communications.

"He's home resting," Nelson said last night.

But not for long. According to Nelson, Paterno was still planning to fly to Austin, Texas, today to be the keynote speaker at a function for Texas coach Mack Brown.

It has been a busy week for the legendary coach. On Friday and Saturday, Paterno was in King of Prussia for a Nittany Lion Club fund-raiser. He returned to State College that night and had Sunday breakfast with recruits in town for the Nike Camp. Then on Monday he traveled to Chicago for the Big Ten coaches' meetings.

Paterno returned Wednesday evening, spoke to two of the Nittany Lions' latest recruits yesterday morning, but felt ill later on, said team spokesman Guido D'Elia.

"It's a busy time, and he's been pushing it," D'Elia said.

Paterno was not admitted but was subjected to a full array of precautionary tests, D'Elia said. His wife, Sue, and daughter, Mary Kate, were with him.

"He's in good spirits," D'Elia said before Paterno was released. "He's dying to get out of there. He's mad as heck. He doesn't like to lose time."

Paterno's son, Jay, was on a recruiting trip in Ohio yesterday and said he hadn't heard of his father's trip to the hospital until a reporter contacted him. The Penn State quarterbacks coach said he then called his sister and had any concern immediately quelled by the elder Paterno.

"I asked my sister if there was anything he wanted to say to me and he said to her, 'Just tell him to keep working,' " Jay Paterno said. "He didn't even want to talk to me, so obviously there's no worry."

Paterno's health has come under increased scrutiny since November 2006, when his left leg was broken during a sideline play at Wisconsin. He missed the following game and coached from the press box for the rest of the season.

He returned for the 2007 season opener, though, running onto the field with his players, as is his custom. But Paterno's 42d season as Penn State's coach was a taxing one, especially with mounting off-the-field issues.

He admitted as much the day after the Alamo Bowl in December. "It's been a very difficult year for me physically," Paterno said then. "I'm still fighting some bumps and bruises. I get tired."

A few weeks later, he caught the flu and was sidelined for almost three weeks, missing most of the recruiting high season. He was very involved during spring practice, but this latest setback could add fodder to those who believe Paterno is too old to continue coaching.

While not commenting specifically on Paterno's condition, Jason Karlawish of the University of Penn Hospital's Division of Geriatrics, said that a person 80 years or older has a more difficult time recovering from dehydration than, say, a 30-year-old placed in a similar situation of stress.

"It's the plain facts on the physiology of aging," Karlawish said. "Let's put it this way, it has a much greater effect on [Paterno] than it does on his football players."

Paterno has insisted that he feels fine and that he hopes to coach for more than two years and maybe for as many as five. He is in the last year of his contract and will not know his future until after the conclusion of the coming season.

Last month, university president Graham Spanier said that Paterno would not be given another deal, but that his unique situation could allow for him to continue coaching without a contract.