Several lakes in Mexico are temporarily closed following confirmation of a deadly brain-eating amoeba, *Naegleria fowleri*. The closures affect artificial lakes within luxury resorts in the Yucatán region, originally intended for water sports. The decision comes after analysis of a recent fatality confirmed the presence of the amoeba. Authorities have not yet specified which lakes in Mexico are affected, or the duration of the closures. This represents a significant public health concern, as *Naegleria fowleri* is a rare but almost always fatal infection of the brain. Further investigation and monitoring of water quality are underway in the Yucatán.