Hi I'm a 27 year old Female who has recently started exercising (high intensity interval), I noticed that after a couple of sessions I had these red marks on my stomach, I thought it was from where I was resting weights in between reps. As I mentioned in the title they don't hurt, they're not itchy or scaly they are completely flat and appear to just be red marks. In the last week however they have started to appear all over my back, just above my buttocks, in the crack of my buttocks and after exercising yesterday I noticed a couple on my arm and leg. I thought it might be something to do with heat, sweat or contact? There is a 2 week waiting time for my doctors so I thought to come and ask here if anyone has any idea what it could be and if there is anything I can do? Thanks very much and I am sorry for the rubbish pictures!