The cord leading to my electric blanket doesn’t heat up. Neither does the 100 or so feet of cable leading to my bedroom from the breaker box. But how are the wires inside the blanket designed to heat up but do so safely? Is it just a matter of tuning the thickness of the wire to get the right cross-sectional area to allow it to heat up yet not burst into flames?
Bonus question: does house wiring in Europe have to have to be double the cross-sectional area of the US due to the higher voltage?