The hospitals of Morecambe Bay NHS foundation trust want members of the public to be on the lookout for symptoms of norovirus.
Norovirus, also called winter vomiting disease, usually occurs during the winter months, and usually start to appear during the autumn.
It is the most frequent cause of infectious gastroenteritis in England and Wales and typical symptoms are vomiting and diarrhoea.
People suffering will feel very unwell initially but will usually improve quickly as the symptoms settle.
Sian Beard, matron for infection prevention, said: “If someone suspects they have norovirus they should ensure they do not visit hospitals, schools or care homes to reduce the risk of them passing it on to others.
“They should also avoid work – and only return after they have been free of diarrhoea and vomiting for at least 48 hours – during this time infectious viruses may still be present.”