Menstrual cramps are caused due to the shedding of the inner lining of the uterine wall, witch will be quite painful when the body is cold, every time I got worse cramps when I got colder. Then I got one thing which just saved me, that is EmrysHome & Flexwarm Menstrual Pain Relief Heat Belt,it is a uterus warming belt which can heat up by far-infrared intelligently. Very ulitity and portable. It really helps me a lot.