The Italian law, through a specific government decree (d.p.r. 37/97), recommends the minimal technological, structural and organising requirements that surgery rooms of public hospitals must assure. Nevertheless, thermal comfort is usually evaluated by the indices PMV and PPD (Fanger's indices). Microclimatic data, acquired inside 80 surgery rooms over 20 public hospitals located in South of Italy, have been reviewed taking into account the new version of the international standard UNI EN ISO 7730. This version enables to classify the workers in three categories, A, B and C each one related to a different value of the acceptable number of dissatisfied people PPD. Considering the particular task which surgeons and nurses are involved in, a percentage of dissatisfied < 6% appears more realistic and conservative respect to the 10% prescribed in the old version of the standard. So the calculations show that, in this case, less than 17% of the staff would considered the thermal conditions as comfortable. Furthermore, the range of the microclimatic parameters, as established by the low, is not sufficient to assure thermal comfort using the PMV or PPD.