California's new virus message: 'Don't share your air'

Phlebotomist lab assistant Jennifer Cukati cares for a COVID-19 patient inside Sutter Roseville Medical Center ICU in Roseville, Calif., on Tuesday, Dec. 22, 2020. The patient came in the night before "code blue" and COVID-19 positive. His heart stopped and he had to be intubated, and is on a respirator. The state has recorded a half-million coronavirus cases in the last two weeks, and Gov. Gavin Newsom said Monday that a projection model shows California could be facing nearly 100,000 hospitalizations within a month. (Renee C. Byer/The Sacramento Bee via AP, Pool)

A volunteer works in a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

Engineers and volunteers stand outside a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

Volunteers help set up a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

A pedestrian wears a face mask while walking past the skyline during the coronavirus pandemic in San Francisco, Monday, Dec. 21, 2020. (AP Photo/Jeff Chiu)

Phlebotomist lab assistant Jennifer Cukati, right, and Registered Nurse Carina Klescewski, left, care for a COVID-19 patient inside the Sutter Roseville Medical Center ICU in Roseville, Calif., on Tuesday, Dec. 22, 2020. The patient came in the night before "code blue" and COVID-19 positive. His heart stopped and he had to be intubated, and is on a respirator. The state has recorded a half-million coronavirus cases in the last two weeks, and Gov. Gavin Newsom said Monday that a projection model shows California could be facing nearly 100,000 hospitalizations within a month. (Renee C. Byer/The Sacramento Bee via AP, Pool)

Engineers and volunteers help build a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

Volunteers help build a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

Volunteers help set up a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

A mobile field hospital is set up at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

FILE - In this July 7, 2020, file photo, hospital staff members enter an elevator with the body of a COVID-19 victim on a gurney at St. Jude Medical Center in Fullerton, Calif. When Gov. Gavin Newsom provided a dire view of California's out-of-control surge of coronavirus cases and hospitalizations this week, he referred to projection models of future death and misery were becoming "alarmingly" more accurate. If true, then within a month the state's hospitals could be overflowing with 75,000 patients, about five times the current level and an average of 400 people will die every day. (AP Photo/Jae C. Hong, File)

A mobile field hospital is set up at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

Engineers and volunteers gather around ventilators while setting up a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

A mobile field hospital is set up at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

A mobile field hospital is set up at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

Volunteers help set up a mobile field hospital at UCI Medical Center, Monday, Dec. 21, 2020, in Orange, Calif. California's overwhelmed hospitals are setting up makeshift extra beds for coronavirus patients, and a handful of facilities in hard-hit Los Angeles County are drawing up emergency plans in case they have to limit how many people receive life-saving care. (AP Photo/Jae C. Hong)

FILE - In this Dec. 14, 2020, file photo, California Gov. Gavin Newsom holds up a vial of the Pfizer-BioNTech COVID-19 vaccine at Kaiser Permanente Los Angeles Medical Center in Los Angeles. When Gov. Newsom provided a dire view of California's out-of-control surge of coronavirus cases and hospitalizations this week, he referred to projection models of future death and misery were becoming "alarmingly" more accurate. If true, then within a month the state's hospitals could be overflowing with 75,000 patients, about five times the current level and an average of 400 people will die every day. (AP Photo/Jae C. Hong, File)

FILE - In this Dec. 17, 2020, file photo, medical tents are set up outside the emergency room at UCI Medical Center in Irvine, Calif. When Gov. Gavin Newsom provided a dire view of California's out-of-control surge of coronavirus cases and hospitalizations this week, he referred to projection models of future death and misery were becoming "alarmingly" more accurate. If true, then within a month the state's hospitals could be overflowing with 75,000 patients, about five times the current level and an average of 400 people will die every day. (AP Photo/Ashley Landis, File)

People wear face masks while walking upstairs at the Golden Gate Overlook in the Presidio in front of traffic driving on the Golden Gate Bridge during the coronavirus pandemic in San Francisco, Monday, Dec. 21, 2020. (AP Photo/Jeff Chiu)