Public Health Isle of Man has also urged those eligible for the flu vaccine to get it.
That included children, pregnant women, those with long-term health conditions, carers, those aged 65 and over and frontline health workers.
Around 47% of eligible residents have taken the flu vaccine this year on the island, the body said.
Director of Public Health, Dr Matt Tyrer, said: “As we head into the festive season, people are likely to mix more and travel to the UK to visit relatives.
“We want to remind everyone to take simple steps to reduce the risk of catching flu or other respiratory illnesses”.
He said people were reminded to practice good hand and respiratory hygiene, keeping their homes well ventilated or staying at home if they feel unwell with the flu.
Symptoms of respiratory illnesses include a high temperature, coughs, sore throat, tiredness and muscle aches.