@carrottop10,
I couldn't tell you, carrot top, but here are a couple of thoughts.
I brought my senior cat home about 12 years ago, and he hid out for two days. He was used to being around people, but the change was more than he could handle all at once. If some domesticated cats will act this way, how much more so might a wild animal. If he's also putting his spines up, he does sound uncomfortable.
Are you giving him a normal hedgehog diet?
Anyway, good luck with your rescue.