Don’t swim in warm freshwater lakes, ponds, rivers or natural springs. These waters may be inhabited by the deadly amoeba Naegleria fowleri that enters the body through the nose and travels to the brain. Symptoms of infection, which include headache, stiff neck, body aches, high fever and loss of smell, begin one to 14 days after contact with the organism.

Self-defense: Avoid swimming in natural bodies of water above 80°F… if you choose to swim, wear nose plugs.

If you think you may be infected: See a doctor immediately. Certain drugs, such as miconazole, rifampin and amphotericin B, may fight the amoeba if administered quickly.