Potassium deficiency is quite common, especially in hot weather for those who don't eat plenty of fruits and vegetables. Fruits and vegetables contain plenty of potassium. In hot weather when someone is sweating heavily they lose plenty of potassium via sweat. Beware of potassium supplements in pill form. They can damage your digestive system. The best idea is to eat plenty or fruits or vegetables rather than take a potassium supplement. If you must take a potassium supplement them get in in liquid form (or a powder than can be dissolved) and make sure to dilute it carefully with plenty of water before taking it.