I definitely second the aloe Vera gel, far more soothing and cooling than creams. Keeping the skin cool will help, if yoy can't tolerate the shower, then dampen some towels with cool water and lay them gently on your legs and you are right to keep well hydrated. I b**nt badly once, about 20 years ago and whilst the redness went fairly quickly it actually took months to heal. I couldn't bend down without it feeling like the skin was ripping on my legs. If you start to feel physically unwell, then I would seek medical attention.