Hi Bob,
I was running the E7's using TMCC, with a max. of 18 volts. It wasn't hot enough to melt anything, but it was hot, especially when compared to my other locomotive, which tend to run more on the cool side. This reminded me of my Lionel 671 which would get hot after a similar length of time. Though, the E7's don't smell of ozone and hot oil.
Lou