Lay low

'Lay low' is what people tell you to do when you're sick, which means to rest and do as little as possible. However, this is a change-in-progress, because people lie and things lay. But it would sound quite odd to hear a native speaker of American English say, "Lie low."

Example:
-I feel awful. I have a fever, a stuffed up nose and a terrible cough.
-You'd better lay low for the next few days. Hope you feel better!