[Dr Morbius]

If you put the fan motor in a mask, then yes, it will overheat. If you extend the "reach" of the motor above it and onto a styrofoam wighead that holds the mask, the motor would then be centered in the middle torso of the prop where it can breath.

This is my setup I used a couple years back. I had no problems at all with overheating. The PVC tee is held onto the fan motor housing with a hose clamp.

 

[Dr Morbius]

Thanks Morbius. But what about when you place the costume on the PVC figure, it still doesn't overheat or did you leave the backside of the figure open to the air? You always come up with very innovative designs for your props.

Thanks for the nice compliment, Richie! I really appreciate that. To answer your question, as long as the costume is light it should be fine. This prop used burlap as a costume. I wouldn't cover the motor with animal skins or heavy plastic as those wouldn't allow any air flow. If you can, try scarefx's linkage. His is really the best solution for oscillating a head. I didn't have the motor required so that's why I came up with the fan/ hoseclamp idea.