‘Direct heat stress’ cases account for about 10% and up to 90% account for ‘indirect heat stress’. While direct heat stress affects people who are directly exposed to the sun during peak summer days, the striking fact about indirect heat stress is that it affects persons who remain indoors and are not directly exposed to the sun. These effects include circulatory overload, kidney failures, dehydration, etc. which causes hospitalisation and even deaths in some cases and yet they are almost never recorded as heat stroke effects.

Workspaces, houses, institutions characterised by heat trapping building materials, poorly ventilated spaces and those with an additional source of heat along with increasing external temperatures owing to climate change creates conditions for indirect heat stress. To cope with the extreme working and living conditions, the need and demand for active cooling techniques increase. And energy demand for the same is mostly met with expensive and unsustainable sources of energy. This reliance on energy sources increases the energy bills and thus exacerbates the financial condition of the people.