At lower temperatures, parts of me get colder than necessary. And there's lots of room for my skin temperature to go up safely that my body is not making use of.

At higher temperatures, I'm already past saturation on evaporation, and the excess just dehydrates me.

> Would it stop you from sweating as much?

Well I sweat less when it's colder. So whatever definition of 'feeling' colder is necessary to cause that effect, that's the definition I choose.

Then you wouldn't want to wear a device that made you feel even colder, would you?

> At higher temperatures, I'm already past saturation on evaporation, and the excess just dehydrates me.

And making you feel cooler would not change that your body is not actually being cooled--if you're at saturation, your body can't cool itself. So to avoid your body overheating, you would need to go someplace that is actually cooler. Just making you feel cooler wouldn't help. (You might get some increase in the time you could stay outside if your body sweated less and therefore dehydrated less.)

Yes I would, because five degrees colder than that is still comfortable, but being wet is not comfortable.

> And making you feel cooler would not change that your body is not actually being cooled--if you're at saturation, your body can't cool itself. So to avoid your body overheating, you would need to go someplace that is actually cooler. Just making you feel cooler wouldn't help. (You might get some increase in the time you could stay outside if your body sweated less and therefore dehydrated less.)

I'm not asking the device to magically prevent overheating. I'm saying that the lower amount of sweat wouldn't be a downside, because there would still be enough.

Also I don't actually overheat because I slow down and avoid pushing myself to that point.

This is a tangent anyway, it's the slightly-over-room-temperature situation that I really care about.