There are 3 ways to get hot water for the Rack Shower: Pour hot water directly into the tank. You can get hot water from your home or heat it over a campfire. Leave the unit in the sun and it will gradually heat the water inside. Connect the Rack Shower to our HyperHeater accessory to get hot water up to 110°F in less than 30 seconds. This is the fastest and most efficient way to get hot water anywhere.