Heat anxiety" refers to worry, discomfort or apprehension triggered by hot weather or high temperatures. It is also known as "heat stress" or "heat-related anxiety". Exposure to long durations of heat results in putting the human body in a stressful state. This activates the body's fight-or-flight response, resulting in increased adrenaline and cortisol levels, which trigger anxiety, agitation, mood swings, and disrupt sleep patterns. Watch this report by NDTV's Apurva Adhikari.