Health authorities in the Cook Islands are advising people visiting the country over the festive season to boil the water.
They said tap water in much of the Cook Islands comes straight from the mountains and with recent heavy rainfall it was possible it could be contaminated.
Health protection officer Charlie Ave said they have a simple message for friends visiting from across the Pacific.
"When they come here they boil the water and let it cool down before drinking, or otherwise we have UV treated water stations around the islands where they can get their water from, or buy it from the shop," said Charlie Ave.
Mr Ave said the message was especially important as they were anticipating more rain for the Christmas weekend.