The world is facing unprecedented humanitarian needs. Today’s humanitarian crisis tend to be greater in number, often in urban settings, longer in duration and broader in regional impact. They generate human sufferings on a greater scale, disrupt essential services, such as water supply or sanitation and put health of large population at risk. Engineers and technical specialists in water, sanitation, energy, environment, and in other related fields play a vital role to respond to these challenges and growing needs. In the humanitarian sector, they are called the public health engineers and today they are increasingly needed! Why public health engineering matters so much in humanitarian crises? And how its related activities are carrying out in such complex environment? This is what this MOOC is all about!