Sen. Charles E. Grassley, the president pro tempore of the Senate, which makes him the third in line of succession to the presidency, revealed Tuesday that he has contracted the coronavirus.

“I’ve tested positive for coronavirus,” he tweeted. “I’ll be following my doctors’ orders/CDC guidelines & continue to quarantine. I’m feeling good + will keep up on my work for the ppl of Iowa from home. I appreciate everyone’s well wishes + prayers &look fwd to resuming my normal schedule soon.”

Grassley (R-Iowa), 87, announced earlier in the day that he would be quarantining after finding out he had been exposed to someone who tested positive for the virus.

The senator was at the Capitol on Monday and spoke on the Senate floor, taking off his mask to do so.

Grassley’s illness follows news late last week that fellow octogenarian Rep. Don Young (R-Alaska,) the dean of the House as the longest-consecutive-serving member, was diagnosed with the coronavirus.

Also, Rep. Cheri Bustos (D-Ill.) and Rep. Tim Walberg (R-Mich.) announced Monday that they had each tested positive and would be working from home. Other lawmakers, including Sen. Rick Scott (R-Fla.), are self-quarantining after being exposed to someone with the virus.

Grassley opened the Senate shortly after 3 p.m. Monday. He spent two minutes on the rostrum presiding over the chamber and then delivered brief remarks, calling on Americans to wear masks, socially distance and “step up their personal responsibilities.”

“We’re going to get through this together,” he said, “but we need everyone to do their part.”

At no point during these remarks or other times on the Senate floor was Grassley seen wearing a mask.

A fierce debate broke out on the Senate floor Monday on the subject of whether senators should be wearing masks while in the chamber. Sen. Sherrod Brown (D-Ohio) asked Sen. Dan Sullivan (R-Alaska), who was then presiding over the Senate, to “please wear a mask” while in that role.

“I don’t wear a mask when I’m speaking, like most senators. I don’t need your instruction,” Sullivan said.

“I know you don’t need my instruction, but there clearly isn’t much interest in this body in public health,” Brown responded.

Later, Sen. Ted Cruz (R-Tex.) tweeted that Brown’s request was “idiotic” and that the Democrat was being “a complete ass.”

“He wears a mask to speak — when nobody is remotely near him — as an ostentatious sign of fake virtue,” Cruz said.

Several Democrats chimed in that stenographers and other staffers sit close to the person presiding over the chamber.

Sen. Roy Blunt (R-Mo.), chairman of the Senate Rules and Administration Committee, confirmed that Grassley also attended a Monday meeting of the top Senate GOP leadership but said he was not overly concerned.

“He’s been great about wearing his mask and I think great about taking care of himself, so I think he’s done everything he can,” Blunt said.

Asked if senators have plans to quarantine, Blunt said he did not personally feel the need to do so. “You’d have to ask them. I was like 12 feet away from him at that meeting.”