Why is my dryer getting extremely hot when it is not turned on?

I just bought a refurbished whirlpool cabrio dryer, they just delivered it today, they turned it on for maybe a minute to show it did work. After it was powered off it kept getting hotter, so I unplugged it the plug was not hot, neither was the outlet. After 30 minutes it completely cooled off, so I plugged it in again and left it turned off, simply plugged in and walked away, within 30 minutes it was extremely hot again.