Temperature differences might effect your final product, depending on what material you're using, but should be minimal with a diode. That's more of a fiber laser problem.
Diode lasers are cheap because they skip basic safety measures like being enclosed, so additional ventilation is a must. I use this fan and have the hose out a window, which clears 99% of the smoke and smell. Fumes are no joke, especially if you start cutting wood and engraving tumblers.