If memory serves me, there was a period in the 1970’s when a common meme (for lack of a better term) was, “Wouldn’t that [do something] to your [something].” So not really a pop culture reference to heating pads, but I suspect Schulz was just using a common expression construction for the potential humorous value.
“You can say that again.” (The King on the Wizard of Id paperback compilation #3)