Comment 9 for bug 1367109

It is still nearly unusable without this patch (my macbook gets up to 90°C - even with the proprietary driver it is at 74°C

Link to patch guide:
http://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html

good overview in the arch wiki about this topic:
https://wiki.archlinux.org/index.php/MacBookPro11,x#Getting_the_integrated_intel_card_to_work_on_11.2C3

On my side its a MacBook Pro 11-3 late 2013 on Ubuntu Gnome 17.04