Due to the controversy related to the necessity to wear protective masks and the negative perceptions of users, an attempt was made to analyze the available scientific research on the physiological consequences of wearing various types of masks. The literature review includes publications available in the PubMed bibliographic database, describing symptoms and complaints of mask users (e.g., the feeling of discomfort, fatigue, headaches), different physiological reactions depending on the type of mask (surgical masks, masks with an exhalation valve, with air flow, etc.) as well as the influence of air composition, temperature and humidity in the space under the mask. The impact of using the mask on the ability to exercise (maximal effort, moderate effort) and mental work was outlined. The consequences of wearing masks by people in a different physiological state (pregnancy) were discussed. Proposals for the organization of work were also presented in order to minimize the negative consequences for people wearing masks. The analysis of the presented studies shows that, regardless of the type of masks worn, they can intensify the body’s reactions to a varying degree, increasing the physiological cost of work and worsening the ability to make both physical and mental effort. In addition, the mask can contribute, among others, to more frequent headaches, symptoms of fatigue or the subjective feeling of discomfort. However, despite these adverse effects, the use of masks is important to protect people against harmful factors in the work and communal environments, and during the current SARS-CoV-2 pandemic, it has become a necessity. The discomfort of wearing a mask can be reduced by taking appropriate breaks. It should be emphasized that the rhythm of work and breaks in wearing the mask should take into account the individual limitations of the employee. Med Pr. 2021;72(5):569–89