ive uploaded my profile picture to the picture of my neck currently
Not knowing anything else about you- it sounds like it could be a combination of the heat and an irritation from the metal- I don't recall where to get them, but companies make neck wraps that are cooling and you can wear them around you- it might be worth trying something like that in order to keep the area covered and cool to see if that helps.
it is somewhat blotchy in other areas but mostly just the creases of my arms. It is not head lice. Doesnt appear to be scabies. I have seasonal allergies but never experienced rashes before. Im 30 years old.