We test whether signals of high aptitude offered to high school students shapes the course of their collegiate study. Mapping continuous raw scores from millions of Advanced Placement examinations onto the 1 to 5 integer scoring scale, we apply a regression discontinuity design to understand how...

We demonstrate that heat inhibits learning and that school air-conditioning mitigates this effect. Student fixed effects models using 10 million PSAT-retakers show hotter school days in years before the test reduce scores, with extreme heat being particularly damaging. Weekend and summer heat...