Thomas was admitted to Sibley Memorial Hospital in Washington, D.C., on Friday evening after experiencing flu-like symptoms, Supreme Court spokesperson Patricia McCabe said in a statement.
He was diagnosed with an infection after undergoing tests and is being treated with intravenous antibiotics, McCabe said. She did not provide more details on the nature of the infection.
"His symptoms are abating, he is resting comfortably, and he expects to be released from the hospital in a day or two," McCabe said. "Justice Thomas will participate in the consideration and discussion of any cases for which he is not present on the basis of the briefs, transcripts and audio of the oral arguments."
After Justice Stephen Breyer, Thomas is the second-oldest justice on the Supreme Court at 73 years old. He is the most senior conservative.
Thomas does not have a known history of health issues and has been a vibrant participant in Court arguments over the past two years. He, along with the other eight justices, has been vaccinated and boosted for COVID-19, according to the Court.
The Court is reconvening Monday at 10 a.m. for two weeks of oral arguments. According to McCabe's statement, it appears Thomas will not be participating in the arguments remotely but will still vote in the cases.