There is a difference in the feelings that one gets, so saying numb and tingling feeling. . . that could mean different things to different people. And by assuming that everyone knows what those to terms/ideas are referring to most people panic far before anything is really going "wrong."
I spend enough time in ropes to know what the difference is when I feel it between good pain and bad pain. Bondage/rope bondage/rope suspensions are not meant to be comfty and fuzzy and nothing ever "hurts" when you get tied. That's just my own view on it tho. Clearly I can't state it as well as others out there. . . but knowing the difference between good pain and bad pain will help just about anyone.
Note: I have been tied so tie and fucked that I thought holy shit my arms are gonna have some "serious" damage. It was when I first started out in bondage/rope work. Turns out yes my arms needed a recovery time and yes they had lovely marks for a longer period of time. No damage lasting damage was done and I learned how far I could push my arms/body in a tight tie. . .that and the sex was great. I don't suggest people do this with anyone who doesn't know what they are doing (the out come won't be the same).
~RK~