Climate in all human activities, including military activities has a major impact. Climate factors that military plans, tactics and doctrines, command, select troops, military equipment, clothing, logistics, maintenance, development and support will be affected. In this study, to evaluate the climatic comfort of troops in west Azerbaijan province was used as an index of physiological equivalent temperature. Purpose of the stations in the region, which has 7 stations throughout the period of over 25years (1985-2009) were selected. The data on climatic parameters including air temperature, relative humidity, wind speed, cloud and vapor pressure during the day and hourly were received. Heat and cold stress conditions, climate and comfort in the days and months of the year were assessed by using the PET. The results showed that in the Highlands parts of Province (western and south-east), with the exception of June, July, August and September there are cold stress for the activities of the armed forces. If the Low height areas (eastern parts) between the months of April to November, there are favorable conditions for the activities of the armed forces, But in the months of November to April due to cold stress state conditions are not favorable for troops. Thermal stresses in the province has been very limited and happening only during the months of July and August in Low height areas.