I just see it as a time to be extra careful with communications (but the extent to which it may affect a particular person probably depends on their own chart.)
So if it's a multiple choice test, be sure you don't go too fast and that you really mark the choices you mean. Read essay questions carefully so you don't accidentally miss a subtle point or miss something that you must include in your answer. Double check that you've written your answer clearly so it's not likely to be misconstrued. If the exam is the take-home variety that requires you to email it to the professor, or you must use an online exam system, watch out for technological glitches and make sure everything successfully sends. Keep extra copies at the ready. All stuff one should probably do anyway.
But overall, I wouldn't be overly worried about it, so don't stress too much!