Simultaneously it is better to wear MCR chappals (micro cellular rubber) which will help to transfer the Plantar Fascitis weight evenly in the feet so that the weight will be completely felt in the heel area.
You shall do contrast bath to relieve this pain
. Contrast bath is nothing but keeping in one tub hot water (bearable heat) and in another tub cold water
Ask your father to apply ice in the painful area which would definitely help to greater extent. If still the pain persists then it is better to keep TENS stimulation at one of the nearby physiotherapy