Heating pad caused touch current on newborn

My 8-week-old went through a tongue tie release a couple of days ago and some parents suggested putting an electric heating pad under the changing mat when doing the exercises, which we did on a very low setting. She seemed comfortable but after a couple of minutes I touched her cheek and noticed a humming sensation, the same feeling I sometimes get when touching the metal casing of my Macbook. I immediately plugged off the heating pad and took her off the mat, the humming sensation stopped. I believe she was exposed to very low current possibly and experienced a “tingle current” according to Dr Google. She didn’t show any signs of discomfort, and her heart rate and oxygen levels are fine according to the owlet sock. Would you go to A&E or call her pediatrician tomorrow? It’s late at night here and I am not sure I’m panicking for nothing. I am worried about heart or brain damage most..