According to a Jan. 26 study conducted by smart thermometer company Kinsa Health, travel to Las Vegas is likely responsible for the recent surges in Southern California, Arizona, and Nevada. Using an analysis of anonymized cellphone location data from SafeGraph, Kinsa researchers say that residents of the most affected counties in California, Arizona, and Nevada were up to twice as likely to have traveled to the Las Vegas Strip in December or early January. And for more on where things aren’t looking so good, find out How Bad the COVID Outbreak Is in Your State. Despite Nevada Gov. Steve Sisolak urging people to stay home, tens of thousands of people visited the Las Vegas Strip for New Year’s Eve, the Associated Press reported. Casinos, restaurants, and bars in Las Vegas were allowed to remain open at 25 percent capacity at the time. Right after the holiday, Caleb Cage, Nevada’s COVID-19 response director, told ABC News affiliate KTNV-TV that people who gathered in Las Vegas during New Year’s should assume they were exposed to COVID. “It was a risk to go out on New Year’s Eve. The governor made it clear,” Cage said. And if you’re trying to stay safe, check out why Dr. Fauci Says You Need One of These at Home to Avoid COVID. Kinsa Health collects data from its more than 2 million smart thermometers used across the country. Using this data, the researchers found that the recent Southern California outbreak “coincided with a similar spike in the southern half of Nevada and much of Arizona,” leading them to connect the outbreaks to one another. “Generally, fever is a common symptom of COVID-19, and we can see that days or up to weeks before COVID-19 cases increase,” Jane Putnam, Kinsa’s director of communications, told KLAS-TV, a CBS News affiliate in Las Vegas. “So, it’s a leading indicator of where increases are going to be.” And for more up-to-date COVID news, sign up for our daily newsletter. Travel to Las Vegas may not have been a lone factor in the coronavirus spread, however. Also in the same time period, a new strain of COVID had become more dominant in California. A study out of Cedars-Sinai Medical Center in Los Angeles published on Jan. 2o, which has not yet peer-reviewed, revealed that this strain, called CAL.20C strain, first surfaced in July but did not become prevalent until November.ae0fcc31ae342fd3a1346ebb1f342fcb Seeing as this timeline matches up with the emergence of Southern California’s overwhelming increase in COVID cases, study co-author Eric Vail, MD, the director of molecular pathology at Cedars-Sinai, told The New York Times it was likely due to how easily CAL.20C spreads. “I’m decently confident that this is a more infectious strain of the virus,” he said. So unfortunately, increased travel to Las Vegas likely exacerbated the spread of this newer, more transmissible California variant. And for more on another COVID strain that’s spreading, This Is How Many Cases of the U.K. Strain Are in Your State.