More than 90 percent of India's area is in the "high alert" or "danger zone" of heat waves.
Extreme heat can lead to a 15 percent drop in "outdoor working capacity"
India now "faces a collision of multiple, cumulative climate threats"
Extreme weather was observed almost every day from January to October last year
These include overcrowding in slum populated areas, lack of access to basic amenities such as electricity, water and sanitation, poor health and unavailability of immediate health care