They should just do like I do at work. Explain it to them and when give you that stupid look and nod their heads just walk away because they acknowledged my explanation. If they do something wrong and get hurt I know that I did what I was supposed to. If they can't/won't learn english, too bad, so sad.
I agree totally with this concept; however, there is 1 tiny detail that might prevent this from being a viable solution:
I should say the I am not in the medical field. I work for a commercial printer as a mtce. electrician. If I explain something to one of these !!@$###@s and they nod their head I take that as they understood me. I will swear that they said they understood me because that is what they indicated to me.
My wife is a nurse although this hasn't come up in her practice I will ask her what her hospital's policy is.