I've been practising a lot for an upcoming concert. Before a particularly demanding rehearsal a couple of weeks ago I was able to hit C6 reliably but since then my upper range has been effectively limited to A5 or B5, and my ability to hold notes toward the upper end of that range has been considerably diminished. My jaw muscles are noticeably sore. The concert is in less than a week. How many days of rest might I need before I'm able to use these muscles at their full strength again? Should I limit my playing to a certain amount of time per day, or simply avoid paying high notes? Are there other strategies that might help?
Obviously everyone is different, and it's pretty hard to answer this generally. Your teacher is probably the better person to ask.
However, depending on the stress I have undergone a day or two is enough for lip swelling, jaw soreness and even cut lips ( I get small cuts on the inside of my lip because of one funky tooth )
Take care of your face for a couple days; Ibuprofen and maybe some lip saver or chapstick? When you get back to your horn after a day off make sure you warm up.. play some low long tones, or pedal tones for the first couple days; stay out of the high range.
When you get back to playing, warm up well, stay hydrated, use ice to reduce lip swelling.