Originally Posted by C6H6
Update: I saw my doctor about this and she suggested I try taking Benadryl - which I told her was probably a bad idea to mix with guns. So I will try Claritin next time to see if it helps. We also think it might be a carbon monoxide reaction. I will need to buy an alarm and do some more testing.
It is true that being near a carbon monoxide source will turn your face bright cherry red and you will start to feel woozy and tired. Is there by chance a generator near your range? Maybe large diesel motors without emissions controls? Carbon monoxide doesn't just appear, it needs a source like a gasoline motor or other mechanical device. I don't think a CO2 detector will help you, but it won't do any harm and it's good to have in your house.
In any case, I'd go and shoot the same guns and ammo at a different range and see what happens. No antihistamines when running that test.
You don't mention if the red areas itch. If they don't itch, it's probably not an allergy. Go by your doctor's advice on this.
Also wondering if you wash your face and hands, as we all should after shooting, with soap the range provides. That's another opportunity for reaction, as is a special shooting shirt, hat, etc.
Is there poison ivy or poison oak in the area? Even if you don't touch it, when they mow, the oils get into the air and can get on you. (Same reason you never burn poison ivy or poison oak)
I would start removing variables one at a time to discover what makes the difference.