Acknowledgement: the authors thank Zotov SV, the Сhief Medical Officer of the Specialized Clinical Hospital for Infectious Diseases for his assistance in organizing the study and Ostroushko MG, the Head of the HR Department of the Regional Clinical Hospital № 2, for her assistance in organizing psychological assessment.

Author contribution: Yasko BA proposed the idea and concept of the, systematized empirical data, discussed the results, and wrote the manuscript; Kazarin BV proposed the concept of the empirical study, provided tools to accumulate survey data; Gorodin VN recruited study participants, organized psychological assessment, propsoed the theoretical and methodological basis of the study; Chugunova NA carried out data acquisition and analyzed the obtained data; Pokul LV participated in the discussion of the study design and wrote the draft version of the manuscript; Skripnichenko LS provided rationale for the study and participated in the discussion about delivering psychological counselling to red zone staff; Skorobogatov VV conducted statistical analysis.

Compliance with ethical standards: the study was approved by the Ethics Committee of Kuban State Medical University (Protocol № 12 dated June 29, 2021 and Protocol № 14 dated June 25, 2021); informed consent was obtained from all study participants.