In the Historic Center of Lima, a city founded in the 16th century, thermal comfort is becoming very important in the analysis of heritage buildings with earth construction systems. If we incorporate the use of thermography to this analysis, the results will be more relevant for the preservation of the structural integrity of the building and the comfort of its occupants, a crucial issue in the face of climate change and the need to protect the architectural heritage, many of which are buildings built centuries ago that have changed use, as is the particular case of the Historic Center of Lima. The paper proposes to evaluate the hygrothermal and thermographic conditions of a building typology "Casa Patio", traditional in the Historic Center, using thermal measurement methods with infrared thermography that allow understanding the hygrothermal behavior of the earth construction system, detect heat losses and propose improvements in energy efficiency and comfort inside the building. For this, three methodological phases were applied; Environmental monitoring with temperature and relative humidity measurements in different seasons of the year, use of infrared thermography to identify thermal variations on surfaces and analysis of data obtained where thermal comfort was determined according to ASHRAE and Peruvian standards. The preliminary results indicated that, despite the outside temperatures, the interior of the building remained within a range of thermal comfort, thanks to the hygroscopic properties of the earth material. And with the thermographic images they allowed to identify critical points where intervention in the building is required. Finally, the research provided valuable information for conservation, with which strategies were proposed that complement comfort while respecting the historical values ​​of the building and the long-term conservation of the built heritage of the Historic Center of Lima.