EMT-SLICK, I have been through EMT-IV tech and just currently finished medic. I did have some people in my class who were absolutely terrified to allow someone to practice on them, which in reality now doing it for a while, I dont let anyone practice on me who is starting out, due to not being able to close my hand for 2 weeks. Besides that I believe everyone who is going to be starting IV's on live patients need to be stuck in the class room to know the feeling, so when you do come across a patient who is difficult to deal with or terrified, you'll have a sense of what it feels like and be able to comfort them a bit more such as say "hey Ive had this done to me many times in class, its really not that bad". So if your a person who is just terrified to get stuck for practice in the class room setting, suck it up. But on the other hand if you have had situations of decreased HR or low BP definitely let your instructor know ahead of time. Maybe give it a try with the IV and see what happens, definitely different than giving blood. Good luck in Medic class!