Visitors of two Greater Boston Hospitals last month may have been inadvertently exposed to measles, a highly contagious disease, state officials said Tuesday evening.

Anyone who may be showing early symptoms of the disease, which, at first, resembles a cold or has visited MGH between August 17 and 23 or MetroWest Medical Center in Framingham on August 23 or 24 should be on high alert.

Dr. Alfred DeMaria, an infectious disease specialist at the Massachusetts Department of Public Health told the Boston Globe that a child who was too young to vaccinated and an older person who may not have been vaccinated went to MGH and MetroWest for medical care. It does not appear the patients were connected each other.

Visitors at MGH were potentially exposed in the medical walk-in clinic on August 17 and 19, the emergency department on August 20, and the inpatient areas between August 20 and 23, according to officials.

MetroWest exposures may have occurred in the hospital’s emergency department and inpatient areas August 23 and 24.

Because most Massachusetts residents have been vaccinated, or have already had the disease, according to DeMaria, the concern is for people who may not be immune to the disease. Young children, pregnant women, and those with compromised immune systems, such as cancer patients, may be at risk for serious complications.

DeMaria told the Boston Globe that hundreds of people could have been exposed to the disease.

The health department has advised anyone who may have been exposed and is suffering from a fever, cough, runny nose, or red eyes to call their health care provider before visiting an office, clinic or emergency department. Patients who have been exposed could put more people at risk of exposure.

Measles symptoms occur within 10 days to two weeks after exposure. Initially, the disease may resemble a cold before a rash develops two to four days after initial symptoms develop. The rash typically appears on the head first and moves downward. The rash usually lasts a few days before disappearing in the same order.

People infected with measles may be contagious up to four days prior to the rash appearing and as much as four days after the rash appears.

Photos via Framingham Patch and WGBH