Last night I noticed painful red bumps had formed around my hips right where my underwear/jeans rest. Today, these bumps are all over my body- on my legs, arms, chest, stomach, and armpits. They don't itch at all, but hurt when any pressure is applied by clothes or otherwise. Some seem to have formed small heads while others have not. Some are very small, while others have turned an inch of skin around them red. I was at an outdoor concert two days ago for many hours and I was also in a hot tub two days ago. It doesn't really appear rash-like or like hives. I've never had anything like this happen before. Any info/advice would be appreciated.