Dr Hilary has warned Portugal could soon be back on the UK quarantine list in an urgent travel warning.
ITV's resident health expert appeared on Lorraine this morning to talk about the rise in cases in the holiday hotspot.
New figures show that 21.1 cases of coroanvirus per 100,000 people in Portugal were recorded for the seven days to August 30.
Countries that have a seven-day infection rate of 20 or more cases risk being added to the UK quarantine list.
Watch the video above to see Dr Hilary's latest travel warning on Portugal
"Portugal, 21 cases per 100,000 so just above the threshold where we impose quarantine on people coming back," Dr Hilary explained.
"So that's quite possibly going to happen quite soon.
"So those people that have taken the risk to take a late holiday, they could bear the consequences as a result."
Dr Hilary then went on to highlight the continued wider issue of flying and aviation during this pandemic.
It comes after 193 passengers and crew on a flight from Zante to Cardiff last week have been told they must self-isolate after it was identified as the source of at least 16 Covid-19 infections.
"We still have a problem with aviation," Dr Hilary warned.
"We saw that flight from the Greek island of Zante, 16 cases connected to that one flight, and we heard reports that people weren't wearing masks and the crew weren't able to make sure they were wearing masks.
"If the aviation industry wants to get back on it's feet, they have to make sure people feel safe.
"If we change the law and make it mandatory to wear masks on flights, one photograph of the people not wearing masks and they could be fined.
"It's a bit draconian, but if it protects everybody else then."
Lorraine airs weekdays at 9am on ITV.
