Hey Aman, glad to know that you are concerned about your friend. You may ask her to use a hot water bag, but tell her to wrap it in a towel or soft cover before using it. The other option that she can try is massage. She can probably ask someone to rub her back, it will warm her skin and stimulate her body to release its own, natural painkillers. If she is using essential oils, check with an accredited aromatherapist that they are safe to use during pregnancy.