My 5 year old woke up complaining his cheeks and his chin pains. his cheeks are red. it hurts when he opens his mouth wide or smiles. no fever.

Seek medical consult: What you describe may (or may not) be serious. You should seek medical consultation right away, so that a doctor can get more information, & advise you appropriately. HealthTap consultations are available; just start over & click on Talk-to-Dr. You can choose video or text, & you can upload pictures, or documents such as test results. Or, call your doctor's office. I hope he feels better soon!