Are lightbulbs in a wooden range hood safe?
You need a heat shield if your fixture is capable of taking an incandescent bulb. 

It is an immutable law of nature that if your fixture has an Edison or halogen socket that an old style light bulb could possibly screw into, someone will try that.  

If you want to engineer that concept out of it, then look at IKEA or other LED lighting, particularly low voltage lighting, which is socketless and cannot possibly be accidentally swapped for an incandescent. Given the unbelievable versatility allowed in LED lighting, there's no reason to stay with rather sad omnidirectional "acts like an incandescent" screw-in replacements. LED light is the first kind of light that is not omnidirectional, it's conic, and that's awesome because most applications actually want a cone of light, not a sphere.  You might as well make the most of that feature - for even more efficiency and cool running.

Speaking of cool running, watch your temperatures. LEDs do not like being hot.