The Poludnitsa is a noon demon in Slavic mythology, referred to in English as "Lady Midday," "Noonwraith," or "noon witch." She is usually pictured as a young woman dressed in white, or takes the form of whirling clouds of dust.
She assails those working in the fields at the hottest part of the day, causing heatstroke and aches in the neck, and sometimes even madness. She is a personification of sunstroke, common across the various Slavic countries of Eastern Europe.