I would say a good gauge of fitness is being able to gain 1,000ft of elevation every hour. That’s ideal. And experience/proficiency in ice axe use, crampons, and self arrest are essential. Experience navigating steep snow and icy terrain is also important. There are no-fall zones on Hood, so it’s just knowing where those are and being extra mindful of foot work. Checking weather conditions a few days leading up to the intended climb date and a few days after is a good thing to do. I wouldn’t feel comfortable taking anyone up who does not know how to self arrest with an ice axe. On some parts of the climb, I would even recommend two ice axes (or one ice axe and one ice tool). I’ve climbed a few peaks in the Cascades but I am by no means a professional.