put it in the freezer for about 10-15 mins before plugging it in.. it initializes engines when plugged in (and never again unless it loses power or usb communications request a reset.) only.  

There is a risk here of condensation, but once you get it cold and plug it in and get more engines pretty much until you unplug it again, the risk is arguably worth it.  I use a bag to prevent condensation.

Let us know how high it goes after being that cold.. the firmware basically is very vigorous with engine initialization.. i've found you can generally eek out 2-4 borderline engines by doing this, and each of them will add around 250gh each..