When you enter doctor's offices, hospitals, gyms, and many other businesses in southern California, you will still get your temperature taken before being allowed inside -- a method used for over a year to screen people for COVID-19.
But now the CDC, and some medical experts, say temperature screenings are useless and even misleading.
"Temperature screening will miss many many people with infections," said Dr. Jeff Klausner, a preventative medicine specialist at USC's Keck School of Medicine.
Get Southern California news, weather forecasts and entertainment stories to your inbox. Sign up for NBC LA newsletters.
When the pandemic began, many businesses and medical offices required temperature screenings before letting people indoors, and if you had a temperature over 100.4 degrees, you would be turned away.
But over the course of 2020, the CDC examined cases of 766,044 travelers entering the U.S. who were screened for temperatures and other symptoms. The report says only 1 case of COVID was found for every 85,000 travelers screened.
The CDC has now concluded "Symptom-based screening programs are ineffective."
"I think temperature screenings are problematic because many times people can have Covid without a fever," said USC's Dr. Klausner.
The NBC4 I-Team has found another problem with temperature screenings, specifically with the accuracy of no-touch thermometers used by most businesses.
Last summer, the I-Team's Joel Grover tried out five popular no-touch thermometers sold online, with the help of registered nurse Alice Benjamin, a professor at the Charles R. Drew University of Medicine and Science.
Nurse Benjamin first took Grover's temperature with a standard oral thermometer, which gave a reading of 98.5–within the range considered normal.
But two of the five no-touch thermometers gave a reading of about three degrees less; that's well out of the normal range.
"As a healthcare professional, that concerns me," said Benjamin.
Other medical experts also told the I-Team they also have concerns about no-touch thermometers.
"I think these devices, in general are less reliable and less accurate," said Dr. James Lawler of the Global Center for Health Security, at the University of Nebraska.
Even though the CDC now says temperature checks are ineffective, LA County's Department of Public Health is still recommending that businesses do them.
That could change June 15, when the state of California goes to a full reopening and further updates protocols for preventing COVID-19.
"I think people got in the habit of doing temperature checks," said Dr. Klausner. He added, "It’s tough to break a bad habit."