Visiting hours have been cut at Addenbrooke's Hospital in Cambridge due to an outbreak of norovirus.
The hospital said it had seen a rise in the winter vomiting bug - prompting a restriction in visiting times.
They've urged anyone who has had the virus NOT to visit hospital for at least 48 hours after the symptoms have disappeared.
Medical director, Ashley Shaw said: "We hope people understand that the reason we put these restrictions in place is to help protect our patients by stopping the spread of this virus."
To protect patients, it is important that members of the public do not come to hospital if they have diarrhoea or are being sick.
Visiting times on all adult wards - not just those where there are patients with norovirus - are restricted and details are on the trust's website.
Only two adult visitors per patient will be allowed at any one time, and children will not be allowed to enter wards unless their visit is essential.
No visitors will be allowed on closed wards except by prior arrangement in exceptional circumstances.
If you are planning a visit, call (01223) 245151 to check if a ward is affected.