Comfort index and environmental variables are indicators of thermal stress conditions inside a livestock facility. The environmental conditions of ten different constructive typologies of swine-production facilities with natural ventilation were characterized in a tropical country (Antioquia, Colombia). Temperature and humidity index (THI), enthalpy (H), animal surface temperature (ST), light intensity, and noise level were measured and computed for each typology, which were located at heights above sea levels between 8:00-23:00. Data were analyzed as a function of each typology, geographical altitude, and time of the day. Descriptive statistics, analysis of variance, and contour maps were employed to analyze the data. It was found that more than 80% of the typologies studied presented moderate or critical thermal stress conditions associated with the construction typology, especially in warm and mild-mild climates.