Does anyone know what this is?

[Lyn29]

Just came up out of nowhere, is burning red to touch but everywhere else on the body is cool? Doesn't itch or anything but feels really warm! Any ideas anyone as a bit worried as has came out of no where?

More hopefully clearer photos

Heat rash, nettle rash, hives?
Some kind of allergic reaction would be my guess.

Shingles?

Do you feel unwell?
If not, my guess would be a reaction to something. New washing powder?

Thank you so much, it's a lot darker than in the pictures and very warm to touch that's the only thing that is worrying me. Just came out of no where which was weird to me

I feel ok, was Just worried as I had a shower about 2 hours ago and nothing there and then felt warmth when I sat down to go a loo and just saw those patches.

Had you cleaned the shower with any chemicals?

Take an antihistamine.
Calamine lotion might help if you have any.

Sitting with your laptop on your knees?

I got this when I drank wine once, and since then, get it on my face. It goes red and hot. Apparently its menopause.

Wish my legs were as nice as this☹️

Any chance it could be sunburn? I've seen patches like this when people wear ripped jeans on a sunny day!

I get this since I started peri menopause. If I have a hot shower or bath it comes up anywhere & it’s hot while the white unaffected bits stay cooler. If I’ve been out in the cold, I get them all down my fingers & they’re hot too.

Thank you for all your replies. I think
I am starting my peri menopause so this does make sense. The only thing I did different from before the shower was have 2 beers and eat a chicken roast. I'm laying in bed now and I can feel them burning through my pajamas bottoms but I've took
an antihistamine and im going to go to sleep and see what tomorrow brings. Thank you all for settling my mind