I have the earth smell mats I use in my thermacell, I have never been winded by deer even coming downwind of my position. They aren't going to care about the thermacell smell.
What they will care about is you whacking skeeters and flies off your face as they are spying on the location before moving in.
OK weird thing happened this past Monday pm...sitting on the ground in a chair, not brushed in terribly but pretty well hidden with good camo and backdrop of trees. Had thermacell running on my backpack on the ground, very little wind but what wind was there was supposed to be from my face, but calm for the most part.
Sitting there and a button buck comes walking within 10 feet of me. I think he must have seen my silhouette as he was stomping a little but not spooked, just trying to get me to move. I didn't so he eventually made it out into the food plot. Once in the food plot I was pretty protected from grass so I wasn't worried. He started eating and after a few minutes, I get a big whiff of thermacell scent. And then he looks up, nose in the air. He smelled it too. It made him nervous. He didn't snort, or blow, or anything, just smelled. But he walked right over to the edge of the grass and was looking right in my direction. Smelling away. He stomped a few more times, trying to get something to move but I stayed motionless. He eventually walked to another part of the food plot. I looked down and saw the thermacell putting off a lot of smokey scent, like the mat was dying (it had only been on 30-45 minutes max) and gets that smokey smell right at the end.
Anyway, I turned off the thermacell and the smokey smell went away pretty quick. That button buck then went on through the plot and I was covered up in deer the rest of the evening, including a smallish 8 pt that was chasing the ladies around and keeping them from going in the food plot. I don't think the first buck smelled me as none of the other deer reacted like that, so I have to think it was the thermacell...
Fortunately the skeeters weren't bad at all. But anyone else experience anything like this before?