What is this rash

[chick3]

Hi, I'm just wondering on some advice on a rash I have on my left thigh and also a small patch on the back of the thigh.
It came up around 3 nights ago it can be itchy and sore but this is only usually at night.
I'm feeling fine in my self a bit tired but had diarrhoea past 4 days.
I'm going to ring GP on Monday but just seeing if anyone knows what I could be

Don't take my word for it please, but it sort of looks like a rash I get when I have been scratching my legs

@donutpretzel - I've never had a rash like this before so was a little bit worried! But thank you though it's probably a heat rash or something