Who said "We must use extreme care."?

This quote is attributed to Dr. Emmett Brown.

We must use extreme care. - Dr. Emmett Brown

"We must use extreme care."

Dr. Emmett Brown Patience

"Great Scott!"

"This is heavy."

"There's that word again, 'heavy.' Is there something wrong with the Earth's gravitational pull?"

"If my calculations are correct, when this baby hits 88 miles per hour, you're gonna see some serious shit."

"Patience is a virtue I'm still learning."

"I may be a redhead, but I'm not a hothead."

"Patience is a virtue."

"Patience is a virtue I never learned."