Sen. Chuck Grassley (R-Iowa), the third in line to the presidency, entered quarantine on Monday because he was exposed to COVID-19.
“I learned today that I’ve been exposed to the coronavirus. I will follow my doctors’ orders and immediately quarantine as I await my test results,” Grassley, 87, said in a statement.
“I’m feeling well and not currently experiencing any symptoms, but it’s important we all follow public health guidelines to keep each other healthy.”
Most patients recover with rest or hospital care but a small percentage die. Most who die had preexisting, serious health conditions such as obesity or heart disease.
Grassley, one of the oldest members of Congress, will keep working virtually while isolating at home, his office said.
Grassley was sworn in as Senate president pro tempore in January 2019, making him third in line for presidential succession.

The first is the vice president and the second is the speaker of the House of Representatives.
Several senators have tested positive for COVID-19 since March, including Sens. Rand Paul (R-Ky.), Bill Cassidy (R-La.), and Mike Lee (R-Utah).
Dozens of representatives have also tested positive.
Reps. Cheri Bustos (D-Ill.) and Tim Walberg (R-Mich.) said Monday they'd tested positive for the new disease.
“I have tested positive for the COVID virus. I am experiencing mild symptoms, but still feel well. I have been in contact with my medical provider and, per CDC guidance, am self-isolating,” Bustos, the chairwoman of the Democratic Congressional Campaign Committee, said in a statement, urging people to wear masks and social distance.
Walberg told constituents that he has mild symptoms and is in good spirits.
“It has been more than a week since I have attended a public event. In conjunction with health officials, my office and I are in the process of reaching out to individuals I had contact with before my self-isolation began,” he said in a statement.
“Throughout this pandemic, the work of our health care professionals and frontline workers has been nothing short of heroic, and I continue to be grateful for their dedication. As we enter the winter months, I encourage everyone to remain vigilant and adhere to public health guidelines to combat this virus.”