01/26/2007 at 07:00 AM EST
Blues singer B.B. King has been hospitalized in Texas for undisclosed reasons but is in good condition, a hospital official confirmed to PEOPLE on Friday.
"He has a low fever but is resting comfortably. He's in good condition," hospital spokesman John Coloen told PEOPLE. "We're expecting him to be released this evening or tomorrow."
The 81-year-old singer was admitted to the University of Texas Medical Branch at Galveston on Thursday. King – who in December was awarded the Presidential Medal of Freedom for his musical contributions – is scheduled to perform at a concert on Friday evening that has not yet been cancelled officially.
Paco Vargas, whose restaurant Rudy & Paco is one of the show's major sponsors, told the Houston Chronicle the singer did not leave his tour bus all day Thursday.
About 6:30 p.m. Vargas was ready to dish up snapper and lump crab meat for the singer at his restaurant, right next door to the Grand Opera House where King was scheduled to perform Thursday night. But a member of King's entourage arrived and said the singer wasn't feeling well.
Two doctors – restaurant regulars who happened to be dining there at the time – went to the tour bus to examine King.
After a half hour examination, they recommended he cancel his Thursday evening performance and enter the hospital.