It is important to wear rubber gloves or a plastic face mask when administering first aid:

Rubber gloves... Always. In Healthcare gloved are a number one standard precaution you always wear. It is to keep you from watching a possible disease or pathogenic agent on a patient and also keeps the patient from becoming infected with something you may have on your skin.

A fa e mask is usually only worn when massive amounts of blood are hemmoraghing.

Most of the time yes depends on what your doing

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.