Back to topic:
How will you know???
kp2001 hit it right on the head. You won't. Therefore, consider him one of the lucky/healthy ones.
...
(And please please please don't take this badly....but)...
Your kid is in Big Boy/Big Girl school now.
There are people tasked with monitoring his health. If he feels bad, he can speak up and get assessed/the attention he needs. There are lots of DIs and EMTs around to check on them if they DON'T speak up.
Remember, in less than 18 months from now, your Mid will likely be halfway around the world either navigating literally MANY-MULTI-Millions of dollars-worth of good and military equipment through international waters, or responsible for everything mechanical and electrical that makes it possible (usually with pistons that are wider in diameter than your dining room table).
They will be standing on their own.
---
These are great kids.
They are in good hands.
They have a LOT to learn, and must learn it fast.
MOST of it is difficult, and not pleasant to watch--although the outcome is more that you could have imagined.
And the biggest shocker when we went through this... no more pictures posted on the parents page after Indoc. I was just getting USED to it.