We try to maintain a very good balance. Our teacher sponsor described it very well once as kinda like an apprenticeship program.
Just like I can't turn a 1st year loose inside a piece of 480V switch gear to rack breakers or play with the protective relaying we can't have freshmen running a muck with a plasma torch.
For potentially dangerous tasks the students have to watch a mentor do it a few times and listen and learn, for must stuff we work next to the students and explain and teach as they go and learn. offering advice and pointing out potential issues, better options, whatever.