Silicone masks tend to have issues as well. They typically fit close to the skin and you end up drenched in your own sweat.
Make up is an alternative if you don't mind not being able to slip in an out of it. Many makeups now are sweat proof and there are plenty of zombie tutorials out there for making a wicked looking undead monster. Prosthetics are another choice if you don't mind wearing the face all night, just be sure to use a good adhesive like Pros-aide or some type of medical adhesive.
If you want a latex mask more comfortable though, I'm not too sure. For masks that stick far out from your face, you could install a very small fan to circulate air, but if you're using a snug mask that won't work. Carefully cutting the air holes larger might help somewhat, so you can get more air, but that can be tricky depending on the mask style. Some masks have air holes that can't get much larger without skewing the look of the mask. Sometimes eye holes can be made larger too, though again, that doesn't always bode well for the look of the mask.
You could try putting a painters head smock or two in the fridge or freezer overnight, then wearing them under the mask to keep cool if overheating is an issue. The smocks will usually cover the whole head, but leave the face open so you could wear a mask over it.
I kind of gave up on masks after I got frustrated trying to make them comfortable for myself.