Extreme heat shocks are increasingly linked to poor economic and health outcomes. This paper constructs hour-degree bins of temperature exposure to assess the effects of extreme heat on early child nutrition, a health outcome correlated with educational attainment and income in adulthood. Linking 15 rounds of repeated cross-section data from five West African countries to geo-coded weather data, we find that extreme heat exposure increases the prevalence of both chronic and acute malnutrition. We find that a 2 °C rise in temperature will increase the prevalence of stunting by 7.4 percentage points, reversing the progress made on improving nutrition during our study period.