However, plastic face shields do not provide adequate protection from COVID-19 when used by themselves as an alternative to cloth face masks. Getting the most benefit from a face shield To get the most benefit from a face shield, Henningsen and Edmond recommend these three things: 1. Always wear a face shield with a mask Henningsen explained that face shields give the most benefit when you wear them along with a face mask. Are plastic face shields a better alternative than cloth masks for certain people? Unfortunately, Henningsen said research shows that face shields are only useful as a supplement to face coverings.