Well, this question is right up my alley - as I sell copiers and printers for a living.
Yes, using ink jet medium in a laser printer will burn/melt the medium as drum in a laser printer gets quite hot. More important than that, you will destroy the drum and void any warranties because it was run out of specifications.
On the flip side, if you run laser medium in an ink jet printer, the image will generally not adhere properly. You'll get flaking and pitting because the laser paper has a harder finish and is less porous.
Just remember to look for the medium type on the packaging - it's there for good reason. Hope this helps.