During July 2023 and July 2024, I observed a female Barn Swallow (Hirundo rustica) wet her brood patch and surrounding abdominal feathers at a nearby bird bath, then fly to her nest which contained a clutch of eggs. For both years she wetted herself when the temperature near her nest reached 37.7 °C and periodically continued to wet herself prior to incubating as the ambient temperatures continued to rise.