Explaining the paranormal

Throughout the movie, the conditions the characters find themselves in tend to fluctuate from a mild temperature to a freezing-cold climate.

Shyamalan later explained the sudden and inexplicable drop in temperature was due to angry spirits who expressed their fury by making it bone-chillingly cold.

Meanwhile, the white hair seen on the heads of Haley's Cole Sear and Donnie Wahlberg’s Vincent Grey - the only characters who could see the ghosts - was meant to hint at the idea that every "spirit spotter" would have a common physical attribute.