Authorities warned residents of Lincoln, New Hampshire, to monitor themselves for symptoms of Legionnaires' disease after five people fell ill in June and July.
The New Hampshire Department of Health and Human Services on Monday linked the outbreak of the bacterial pneumonia -- which is caused by inhaling water droplets contaminated with Legionella bacteria -- to a cooling tower behind the RiverWalk Resort in downtown Lincoln.
"Anybody who has visited the area near the contaminated cooling tower should monitor themselves for symptoms," Dr. Benjamin Chan, New Hampshire state epidemiologist, said in a DHHS statement.
"People who develop fever or other symptoms of pneumonia within 14 days after spending time in this area should talk to their healthcare provider about testing for Legionella infection," he added.
MORE: Donated organs likely caused Legionnaires' disease in 2 lung transplant recipients: CDCThe cooling tower has been sanitized and put back into operation after discussion with state officials, RiverWalk Vice President Renee Blood told ABC News affiliate WMUR.
"Out of an abundance of caution, additional testing will be performed later this week," Blood told WMUR. The test results are expected next week.
DHHS said the cooling tower's continued operation could mean further exposure risks, particularly for people within a half-mile of the facility.
"Anyone who is visiting the specified area should assess their health risk," DHHS said. "Those who are older, are current or former smokers, have weakened immune systems, or have certain medical conditions like chronic lung disease and diabetes are at higher risk for developing Legionnaire's disease."
Symptoms usually begin between two and 14 days following exposure and can include fever, cough and shortness of breath. The bacteria can also cause serious pneumonia, the stage known as Legionnaires' disease. The condition can be fatal if left untreated.
DHHS noted, however, that most healthy people exposed to Legionella bacteria do not fall ill.
ABC News' Victoria Arancio contributed to this report.