In 2026 the dates were July 15 and July 25, with the third, 말복 (malbok), falling on August 14. The practice is usually explained by 이열치열 (i-yeol-chi-yeol), the principle of fighting heat with heat. Because malbok is anchored to autumn's arrival rather than counted forward from jungbok, the gap between the second and third dates is usually ten days but sometimes twenty. What the physiology actually saysThe stated logic is 이열치열 (i-yeol-chi-yeol), fighting heat with heat: eat something hot, sweat, cool down. Thermoreceptors in the mouth, oesophagus, and stomach detect the heat of what you have swallowed and trigger a sweating response that is disproportionately large relative to the actual heat you took on.