David Powell, a physician and medical adviser to the International Air Transport Association, gave an interview with Bloomberg on how to prevent catching coronavirus on flights. He was asked if wearing masks and gloves help prevent infections, and his answer is:
First of all, masks. There’s very limited evidence of benefit, if any, in a casual situation. Masks are useful for those who are unwell to protect other people from them. But wearing a mask all the time will be ineffective. It will allow viruses to be transmitted around it, through it and worse still, if it becomes moist it will encourage the growth of viruses and bacteria. Gloves are probably even worse, because people put on gloves and then touch everything they would have touched with their hands. So it just becomes another way of transferring micro-organisms. And inside the gloves, your hands get hot and sweaty, which is a really good environment for microbes to grow.
If you do insist on wearing a mask, read out mask comparison guide on preventing coronavirus infectionfirst