Getting wet in the rain does not directly cause illness
, as sickness requires exposure to viruses or bacteria, not water. However, staying in cold, wet clothes lowers your body temperature and weakens your immune system, making you more vulnerable to infections if you are already exposed to viruses.
George Boole died in Cork on the 8th December 1864 following a short illness. On the 24th November 1864 Boole was caught in heavy rain on his way from his house in Ballintemple to lectures at Queens College, a distance of approximately 3 miles. Instead of changing his clothes, he continued teaching through the day, and subsequently caught pneumonia from which he did not recover.