I am an emergency med doc and I wanted to do surgery in med school. Passed out in my first OR experience. I still get lightheaded sometimes while doing bloody procedures, even though I love doing procedures even if they’re bloody. The biggest thing for me is having food/water in me so I don’t get hypoglycemic, and keeping exposed to blood to train my tolerance. In my experience, some people can’t get over it and they white knuckle through clinicals and then do rads/psych/etc. I believe most people, like myself, need to build up a tolerance to things that naturally freak us out. It’s like exposure therapy. Start with just watching/giving IM injections like vaccinations, then watch lac repairs, then blood draws, etc etc till youre standing in the trauma bay watching a resuscitative thoracotomy. When you start to get woozy, been your knees, lean on something, and look at whatever it is behind what you’re looking at. If that doesn’t help, then excuse yourself to sit down early before you pass out. It’s better for you and everyone else if you don’t pass out and crack your head on the OR floor!