Communities in the high-altitude region of the Peruvian Southern Andean Mountains are located over 4200 meters above sea level. Communities organize in isolated cabins dispersed in an extensive area surrounding the community center. The harsh natural environment and poor living conditions affect people's health and increase child mortality, especially in winter. Daytime solar radiation is of high intensity. At night exterior temperatures are-10 C, while indoor temperatures of cabins barely reach 0 C. This research sought to improve the thermal performance of these cabins with passive design strategies and local resources. The methodology included: a) collection of weather data versus indoor thermal performance, availability of local resources and understanding domestic organization patterns; b) definition of comfort temperature range and analysis of local materials; c) technology transfer by involving the population in the construction of a prototype. Simple passive strategies of air tightness and solar gain with local available materials (adobe for walls, totora reed (Schoenoplectus tatora) and sheep wool for insulation, and stone and wood to waterproof the floor) improved night thermal performance in these isolated areas. Although local people are starting to implement these techniques in their own cabins, this is just the starting point towards appropriate thermal comfort.