They reduce viral transmission (if worn correctly). ...
They prevent asymptomatic spread. ...
You're protecting others from illness. ...
They're mandated by law in some states. ...
They're good hygiene in general.
Answer: It’s important because people go to the doctor when they don’t feel good, and sometimes it’s a virus, and sometimes it’s just bacteria.
c) are often metals
liquids are fairly good thermal conductors while gases and things like wood and plastic foam are poor conductors of heat.