Northern Ireland's Chief Scientific Adviser has recommended that people wear face coverings when they are out in public.
Professor Ian Young, who is a member of the Government's Scientific Advisory Group for Emergencies (Sage), has called for more people to use the protection when they are in an enclosed space.
He was giving evidence at the Stormont health committee yesterday when he said: "I would like to see a lot more people wearing masks. I'm almost the only person wearing a mask when I'm in the supermarket. People should be wearing a cloth face covering when they're in an enclosed location."
Prof Young was also asked about the efficacy of taking peoples' temperature when they arrive at work.
He voiced concern over the measure which he said has limited value in preventing the spread of the virus.
Referring to a review of monitoring temperature, Prof Young said: "It suggests that we may pick up a quarter of people who are currently infectious through checking temperature, but at the price of identifying a lot of people who aren't infectious and telling them to go home and isolate.
"It's open to manipulation if people wish to do it. They can put a cold face cloth over their face or take a couple of paracetamol, although I hope that people don't do these sorts of things.
"It's something that may have some value but we don't think it's particularly useful at the moment."
Last month, Prof Sian Griffiths, who co-chaired the Hong Kong government's inquiry into the 2003 Sars outbreak, recommended that people in Northern Ireland should wear face coverings to help prevent the spread of Covid-19.
"I think they may contribute to protecting other people who come into close contact with you," said Prof Griffiths.