Why does this always happen?

I'm not particularly worried, just curious. Every time I have a shower I get red blotches all over my shoulders, a bit on my back and my face but nowhere else. I thought it was just because of the direct stream of warm water hitting my back and shoulders but I face away from the shower so it doesn't hit my face. I always shower with the temp on the lowest it can go but that's still pretty hot for some reason (awkward shower 😂). I'm assuming this happens to everyone, I could be wrong. Why does this happen? Is it me? Can I stop it?