Some lockdown restrictions could be reintroduced in Wales this winter should coronavirus make a resurgence, Wales' health minister has warned.
Vaughan Gething said it will all depend on the "reservoir" of Covid-19 which exists at the time, as well as people's behaviour.
His comments followed a statement from Wales' chief medical officer Dr Frank Atherton who warned that the virus is "likely to thrive in cooler, indoor environments particularly where people gather closely together".
Dr Atherton recommended that messages to the public highlight "the potential need to re-impose more restrictive measures in the winter if viral activity increases".
Speaking as part of his weekly press conference from Cathays Park, Mr Gething said: "Some of the measures that we've been able to unlock are because of the time of year we're in.
"We know that coronavirus lasts a lot less in direct sunlight outdoors but lasts a lot longer on indoor surfaces.
"We do need to think about the fact we may have to reintroduce some lockdown measures in the winter.
"There isn't a hard or fast set of measures, but we will have to look at the evidence that we get. This will include not just the people who test positive with our expanding programme, but also numbers of hospital admissions and the number of people in critical care."
Mr Gething admitted winter is likely to be a difficult time for the NHS because more people are likely to be indoors where Covid-19 can spread more easily.
Meanwhile, during the press conference Mr Gething said there would be a gradual resuming of some "essential" NHS activity, including planned NHS operations and cancer services.
"In resuming services we do not mean returning to doing things as they would have been done in February of this year," he said.
"We simply cannot have packed-out patient waiting rooms because people are being automatically recalled every six months for repeat follow-up appointments.
"As we restart essential activity, we will keep many of the systems we've put in place during the pandemic, including for example the telephone triage system in general practice and online video consultations wherever possible."
Mr Gething added that dedicated facilities and zones would be set up with strict infection control in place in a bid to separate Covid-19 patients from everyone else.
He said health boards in Wales have been looking at how they could restart planned NHS operations and cancer services, more details of which would be published tomorrow (Wednesday).
The minister confirmed a £150,000 fund had been launched to quickly trial new digital methods of working.
He also said a review is set to be carried out into whether Wales' 19 temporary field hospitals can be used for routine NHS work.
Public Health Wales (PHW) confirmed on Tuesday that the total number of fatalities since the pandemic began now stands at 1,354.
