Fever checks have widely become the first level of coronavirus detection as businesses, stores and schools try to reopen, but experts caution that relying on them as a single screening tool could lead to a false sense of security. … While a temperature check can detect people who are showing symptoms, there are a significant number of people who could be contagious that don't develop a fever, said study co-author Peter Kuhn, a professor of biological sciences, medicine and engineering at USC.