Rising Covid numbers have prompted two Welsh health boards to ask staff and visitors to wear face masks in their hospitals.
Office for National Statistics figures show infections were at their highest in Wales for a month in the week up to 11 June.
Now Aneurin Bevan and Cwm Taf Morgannwg boards have asked people to wear masks at all or some of their hospitals.
The BBC has asked Wales' other health boards if they are taking any action.
On 30 May, the necessity to wear a mask in health settings was the last of the Welsh government's coronavirus rules to go.
Aneurin Bevan said the move was driven by "the increasing prevalence of Covid-19 in the community, the increased number of Covid-19 ward outbreaks and the numbers of staff absent with Covid-19".
It said it would continue to review the policy, which has been implemented with immediate effect, and update people accordingly.
Cwm Taf Morgannwg health board said it had an increasing number of patients with Covid in two of its hospitals, Royal Glamorgan and Ysbyty Cwm Rhondda.
To protect patients, staff and visitors it said it was asking staff and visitors to wear masks in all areas of those hospitals, as well as socially distancing as much as possible.
This too has started immediately and will be reviewed daily.
Hywel Dda health board said it was not a legal requirement for visitors to wear masks, but "from time to times it may be necessary to ask visitors to wear additional PPE, such as face masks, to help minimise the risk of spread of infection in hospital".
It added: "Any requirement to wear PPE will be communicated clearly by the nurse in charge of the ward."
A Public Health Wales spokesman said although it did not run any wards or clinical areas in hospitals, its screening division programmes did work in hospitals, so its staff would "follow local guidance which includes the use of face masks in some places".
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