Basing on the analysis of 304 cards on work conditions it is found that work tension (Class 3.3) is the leading hazardous production factor at workplace of unit operators at thermal power stations, increasing the risk of development of the CVS pathology. Microclimate and noise parameters are classified, on the average, as hazardous of Classes 3.2 and 3.1, respectively, but at the third part of the work places it exceeds mean group levels and can be considered primarily as harmful for Classes of 3.3 and 3.2, respectively. The heaviness of the work performed can be referred to Class 3.1 due to expressed hypodynamia.