A medical specialist wearing a protective glove puts a pulse oximeter on a patient's finger in the Central Clinical Hospital "RZD-Medicine", which delivers treatment to people infected with the coronavirus disease (COVID-19), in Moscow, Russia May 18, 2020. Sofya Sandurskaya/Moscow News Agency/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. MANDATORY CREDIT. - RC2YQG9WX0J7