Residents in Barry have been warned to take precautions after a 'cluster' of Legionnaires' disease was declared in the area.
Eleven cases of the disease have emerged in the Vale of Glamorgan over the last 12 months.
Public Health Wales say there's no evidence the cases are linked.
The situation has been labeled a 'cluster' as it does not yet qualify as a Legionnaires' disease outbreak.
Legionnaires' disease is caused by a bacteria called Legionella and can often begin with flu-like symptoms. It can lead to pneumonia.
How you can reduce the risk of Legionnaires' disease?
Regularly flushing through or removing unused taps and shower heads.
Draining water bowsers and garden hoses.
Using commercial screen washes in vehicles.
What are the symptoms to look out for?
high temperature - feverishness and chills.
Signs of mental confusion.
There are on average 30 cases of Legionnaires' disease in Wales every year.