UVC can damage RNA & DNA so really dangerous to human beings, there is almost no natural UVC radiation in the enviroment , UVC rays that exist stablely were made by human being.
See picture below UVC rays damage DNA process:
So how do we protect ourself from UVC radiation rays ?
UVC can only pass through quartz glass, so even a paper can block it easily, see video below:
Not only UVC can damage skin, it is harmful to eyes too, so we need to wear anti-uvc glasses as below:
So in conclusion :
Long sleeves to ensure no skin exposure to the UVC rays
Wear anti-uvc glass to protect your eyes.