it matter what the ribbon cable they used is made out of.
if its brown and hard plastic, its probably acetate (i think thats the right word, right?) and it will be fine to the heat.
the issue is, if they used something else to insulate the ribbon cable, it may melt really quickly causing irreparable damage.
if it is the brown cable like in a DMG, it should be fine.
i'd look, but have to run out the door in a sec and if i dissect a gameboy i'll get lost in it and miss work...
EDIT - my response is really geared towards if you asked "can i destroy the LCD screen?"
heat will destroy an EL backlight, yes, just like it would an LED one. however, provided the glass from the LCD is between your heat source and the EL, unless you go crazy with the heat you should be ok.