I spent about an hour and a half in the sun this afternoon and I've got burned shoulders and the back of my neck is also burnt. I've been home for almost 8 hours and haven't been out again, have had a nap, some food with salt in and a fair amount to drink. I'm panicky that I'll get / have gotten heatstroke but everything I've read online says it happens very very quickly.....would I have started to be ill already if I had heatstroke?