Legionnaires' disease.

Legionnaires' disease is a severe and potentially life-threatening form of pneumonia caused by the bacterium Legionella pneumophila. It typically spreads through inhaling contaminated water droplets, often from sources like air conditioning systems, hot tubs, or water fountains. Symptoms can include high fever, cough, shortness of breath, muscle aches, and confusion. Prompt medical treatment with antibiotics is crucial for recovery. It's named after an outbreak in 1976 when it affected attendees of an American Legion convention in Philadelphia.