People should wear face coverings when social distancing cannot be maintained, Wales' health minister has said.
Under guidance from its chief medical officer, the Welsh government has advised the use of face coverings where people cannot stay 2m (6ft 6in) apart.
But minister Vaughan Gething said there was "insufficient evidence" to support widespread use of medical masks.
Anyone shielding "should wear a medical mask" on entering a health or social care facility, he said.
Mr Gething said medical-grade masks "should be reserved for use during the direct care of patients or residents".
It remained of "paramount importance" for health and social care staff to observe social distancing and good hand hygiene practices, he said.
The minister said he accepted that "medical masks have a place for the protection of the vulnerable in higher-risk settings".
He had agreed, therefore, that shielded people in Wales should wear a medical mask upon entering any health or social care facility, "although this need should be minimised where possible," he said.
"When other members of the public need to enter such facilities, they can of course wear a face covering if they wish to," he said.
While medical masks were an "essential part of personal protective equipment during direct care", Mr Gething said, their wider use could have "adverse consequences" if they replaced social distancing.
"There is little evidence that the more widespread wearing of medical masks benefits either staff or the public," he said.