on prior bikes that I put HID on the ballast wasnt a heat issue. The bulbs themselves may be depending on the construction of the lamp and , of course, you need to run a new power wire for them from your battery or distribution box as the stock wiring wont be good for the power needed for the ballast long term usually. If I upgrade the Ultras lightg I will probably try the LED type now that they are bright enough..no heat or power issues.