I have dry skin and in the winter i develop hives when anything touches my skin or when i'm cold or when i'm exercising. ?

Hydration & moisture: dry skin in winter is common, in your case you may have urticaria, an allergic skin condition of several types, and gets stimulated by different agents, temperature change is a powerful physical agent in such cases, you need to see a dermatologist or an allergist, meanwhile keep yourself well hydrate even in winter, moisturize your skin well right after bathing with a cream saop, goodluck