Hello :) If the foal is in good health there's no reason he couldn't go outside or even stay in the field 24/24. If he has a disease that retain him to stay in a stable then at least doing hand walks is the best!
Hi Melinda !
I think it is better to let a foal go outside as soon as possible, so that he can discover and play more. He will go outside sooner or later so he will be calmer if he has seen a lot of things since his young age!