Hot water means HOT!!
Given this is a volcanic island the water comes out of the ground practically boiling. Consequently they do not have hot water heaters. Rather you spend your time managing the cold water flow in the shower to prevent scalding.
The downside is the sulphur smell. A small price to pay for unlimited and extremely cheap hot water. All of us could take showers in the morning, right after each other, and still have plenty of hot water.