Legionnaires' disease is a type of pneumonia contracted by inhaling mist from infected water, according to MedlinePlus. General practitioners can treat Legionnaires' disease with antibiotics.
Legionella, the bacteria that causes Legionnaires' disease, thrives in warm water. Hot tubs, decorative fountains and cooling towers are good hosts for Legionella. Legionella does not appear to grow in car or window air conditioning units, as reported by the Centers for Disease Control and Prevention.
Symptoms of Legionnaires' disease include cough, fever, muscle aches, headaches and shortness of breath. Symptoms usually appear one to two days after exposure to the bacteria. In most cases, the symptoms clear on their own, states WebMD.