Amphibians are the most extinction-prone clade of terrestrial vertebrates. Amphibians have declined not only in areas affected by deforestation, but also in seemingly pristine forests with low human impact. These ‘enigmatic’ declines are often associated with the chytrid fungus, but other studies suggest that climate might play an important role in some declines. Ectotherms in the tropics are at special risk of decline because of their narrow warming tolerances (WTs), the difference between an organism’s body temperature and its tolerance to high temperatures (the critical thermal maximum, or CT_max). In this study, we measured population densities and WT in four populations of a tropical lungless salamander, Bolitoglossa altamazonica, at elevations ranging from 500 – 1150 m in the eastern Andes of Colombia. We found a significant, positive relationship between WT and population abundance: population densities increased with WT, which in turn increased with elevation. We report an alarming decline at one lower elevation site, where salamander counts have declined by 70% in the past ten years. As the thermal landscape in the tropics continue to change, understanding species’ response to warming will be crucial for habitat conservation practices.