During a pandemic, may an ADA-covered employer take its employees’ temperatures to determine whether they have a fever?
Generally, measuring an employee’s body temperature is a medical examination. If pandemic influenza symptoms become more severe than the seasonal flu or the H1N1 virus in the spring/summer of 2009, or if pandemic influenza becomes widespread in the community as assessed by state or local health authorities or the CDC, then employers may measure employees’ body temperature. However, employers should be aware that some people with influenza, including the 2009 H1N1 virus or COVID-19, do not have a fever.
Because the CDC and state/local health authorities have acknowledged community spread of COVID-19 and issued attendant precautions as of March 2020, employers may measure employees’ body temperature. As with all medical information, the fact that an employee had a fever or other symptoms would be subject to ADA confidentiality requirements.
https://www.eeoc.gov/facts/pandemic_flu.html (See Section III, SubSection B, Question #7)