Parental care is often energetically expensive and keeping offspring within acceptable thermal limits may be particularly costly for endotherms in temperate and sub-tropical regions where spring temperatures are below thermoneutral zones. We sought to test whether higher temperatures in the arid tropics may mitigate the energetic demands of keeping avian offspring warm, as this possibility remains largely unexplored. Passerine birds develop optimally at ~37-39˚C and birds in tropical dry forest may experience temperatures close to, or exceeding, 39˚C. We also sought to test the effects of nest architecture on thermal requirements for breeding birds in tropical Ecuador. Adults can potentially modify nest temperatures by building enclosed, rather than open, nests if enclosed nests offer greater insulation. Using custom-built circuits, we measured the power required to maintain 39˚C. Nest temperatures were usually close to, and often exceeded, 39˚C in open cup nesting species, but not in an enclosed nesting species. Experimental shading of nests resulted in nest temperatures only rarely exceeding 39˚C in species with either open or enclosed nests. Further, shading meant that the power required to keep a nestlings warm was significantly increased. We demonstrate that high temperatures may be beneficial for the heat balance of tropical birds up to a point. Radiant heat from direct sunlight causes temperatures inside birds’ nests to be critically high (up to ~ 46ºC) for birds breeding tropical dry forest, but when nests were shaded from direct sunlight, they only rarely experienced such critically high temperatures. This suggests, however, that nest-site selection at the micro scale can enable adult birds to mitigate the effects of lethally high temperatures upon nestlings. (NSF: IOS: 1656120).