We assess the effects of temperature on the risk of diarrhoea, one of the leading causes of mortality and morbidity among children under 5. Our analysis focuses on Sub-Saharan Africa, the continent where tem-peratures have been rising at twice the global rate and diarrhoea prevalence rates are highest. Drawing on child-level survey data and exploiting quasi-random variation in temperature realisations around the date of interview, we show that temperature strongly influences diarrhoea incidence as well as preva-lence of wasting (low weight-for-height ratios). Using binned regressions, we document that the effects are particularly strong in the temperature range 30-37.5 degrees C. We further find that access to improved san-itation and drinking water facilities mitigates these temperature-induces risks. This implies that building up such capacities is a particularly pressing issue in regions that will experience strong increases in tem-peratures and lack adequate access to sanitation and safe water. We use our estimates together with cli-mate projections to identify these areas.(c) 2022 The Author(s). Published by Elsevier Ltd.