Ready to use hot shower head, 2 gallon per minute flow rate - 
Similar kinds of things are used in Brasil, except you need to make sure you do not touch the shower head or any metal elements in contact with it, as you will receive quite a shock usually. be careful - richard
Thermophilic compost heaps get hot from bacterial activity. If you coil a long, thin water pipe through compost heap, the water gets heated. The one in the video has 400 feet (122m) of 1 inch (2.5cm) thick hosepipe running through a 2m3 (70 cubic feet) compost heap. This heats water to 90°F (32°C). It stays at that temperature constantly, night and day, and the water quickly reheats after it is used. The hot water could also be used for radiators. Thermophilic compost can get up to 70°C (158°F) if air is pumped in from underneath.