I'm not 100% sure, but I believe a USB-C cable connected to a USB-C charger is cold by default until something is connected. Don't try this at home either, but

I'm not 100% sure, but I believe a USB-C cable connected to a USB-C charger is cold by default until something is connected. Don't try this at home either, but it should also be perfectly safe to plug a USB-C cable into two different wall chargers.