This cross-sectional study conducted from March to June 2020 measured anxiety, depression, and burnout in clinicians working in the United Kingdom, Poland, and Singapore. Approximately 70% of respondents reported feeling anxious, depressed and/or burnt out. Burnout was significantly inversely correlated with being tested for COVID-19 and perceiving high levels of safety. These findings highlight the importance of supporting staff well-being and proactive COVID-19 testing.