Should I go to the hospital?

Im living in dc this summer and I've been walking and sweating a lot. I haven't really been drinking much..I've noticed lately my heart is beating faster than normal..about 110-115 a minute and I can feel it beating which freaks me out. My mom says I need to drink more or go to the hospital for IV fluids if it doesn't get better..but I thought people only went to the hospital for dehydration if they were passing out and stuff. I've been dizzy but that and my heart beat is it. What should I do