Coronavirus updates: 23-year-old college student dies from COVID-19

Iowa Gov. Kim Reynolds announced her state will issue a mask mandate for all indoor activity starting midnight Tuesday.

Reynolds said in a news conference that the state recorded more than 52,000 new cases in the past two weeks, and that one in every four current hospital patients has COVID-19.

"In late October hospitalizations were approaching the 100-a-day mark," the Republican governor said. "Now they have topped 200 a day."

The governor's order "limits indoor social, community, business and leisure gatherings or events to 15 people," and limits outdoor gatherings to 30 people, according to a news release.

"This includes wedding and funeral receptions, family gatherings and conventions," the governor's office said in a statement.

The order will remain in effect until Dec. 11 at the earliest, according to the governor's office.

As of Monday, 188,392 Iowans have tested positive for the virus and 1,991 residents have died from the disease, according to the state's Health Department.

Forty counties in California, representing 94% of the state's population, will move backward into the most restrictive reopening tier, Gov. Gavin Newsom announced Monday.

"This is the fastest increase California has seen since the beginning of this pandemic," Newsom said. "California is pulling the emergency brake."

The new restrictions end most indoor activities. Outdoor dining, gyms, religious services, movies and museums are still permitted. In addition to tightening rules on businesses, Newsom said he was discouraging non-essential out-of-state travel and considering implementing a curfew.

ABC News' Matthew Fuhrman contributed to this report.

More than 1 million U.S. children have tested positive for COVID-19 since the start of the pandemic, according to a report published Monday by the American Academy of Pediatrics and the Children’s Hospital Association.

Last week, nearly 112,000 children were diagnosed, marking the largest weekly increase since the U.S. outbreak began.

Because states differ in how they report on age groups, this report includes infants through teens. In total, infections among children represent 11.5% of overall U.S. cases. Since COVID-19 symptoms in children tend to be milder than those in adults, experts believe many cases go undiagnosed and that current figures are most likely an undercount.

Philadelphia officials announced sweeping COVID-19 restrictions Monday that will last through the end of the year.

Colleges, universities and high schools are required to switch to online learning, and churches have been asked to hold online services. All employees able to work remotely should do so.

Additionally, outdoor gatherings will be limited to 10% occupancy, and food and beverages are not allowed to be served.

"I know these restrictions are tough," Dr. Thomas Farley, Philadelphia's health commissioner, said Monday. "People are going to be put out of work, and some businesses may go under," Farley added. "We also know that the consequences to health of not doing it are really bad."

"If we do this right, our businesses will recover faster because the epidemic wave will subside sooner."

The new rules go into effect on Friday.