When I mist the probe for the thermometer also gets wet and I notice that the temp drops well over 10deg, however the water soon evaporates and it is back to normal… With a temp of 75 I would not feel comfortable misting, however I am sure that they would be fine Veilds can take the cold rather well than most think, but like I said, if it were me I would not just to be on the safe side.
Here is my set up for misting outside. I took a big bucket and hooked up a bunch of cheap misting nozzles to it. The nozzles came from walmart for 12 bucks. Just zip tie them to the sides and drill holes on the bottom of the bucket. I connect the misting tubes to a garden sprayer and let it go for 20 minutes. Also I put a plant in there that is not wide enough to touch the edges. That way my cham can't get out. The plant that's in the pic is not the one I use. I use a small ficus tree.
So far it has been working out fine. I think I'm gonna make another version though. I just got to find a wider bucket or something so she can't get out. This only cost me about $16.