I have been on the birth control pill since august. it messed with my hormones and i gained about 10 pounds when i first went on. for the past few mon?

Consult w/ primary: There are many causes for muscle cramps, but given your age and the fact that you're working in heat, my first thought would be dehydration or an electrolyte imbalance. I would go to your primary care physician and report these symptoms. He or she will most likely order some blood work to see how your electrolytes are doing. Needless to say, when you're out working in heat, it's vitally important.