There is absolutely no need to TYPE IN ALL CAPS, EVEN IF YOUR CHARACTER IS YELLING! Unless it’s a sign or some sort implied warning (such as a caution sign) there is really no need for caps. No one likes to be yelled at when reading.
The best way to imply that your character is yelling or is trying to make a point is to either say that, or italicize the words.
For example:
“John, GET DOWN HERE NOW! YOU’RE GOING TO BE LATE!” is far more annoying than “John, get down here! You’re going to be late!” and you can tell that the speaker is implying an urgent need for John to go downstairs, without having to yell at your readers.
But J.K Rowling did in the Harry Potter books, you object. Yes, but that doesn’t mean it was taken lightheartedly. I hated the ALL CAPS SENTENCES. I know a lot of other people do too.
The only time you really need them are if they are headlines or signs.
Examples:
“Dean read on the morning paper, ‘BREAKING NEWS: BLAHBLAHBLAH CRIMINAL HAS ESCAPED AGAIN!’ and sighed, wondering when they were going to catch him.”
“I neared a large, rustic sign that read, ‘WORTHALL’S FINE JEWELRY’.”
“ ‘CAUTIOUN; THIS ELECTRICITY WILL KILL YOU!’ the sign read, making me nervous.”
Just remember that there are other ways to make your point without having to type in all caps.