Finally revealed the secret of why Katrina is so super hot. Literally at that!

A close friend of the actress reveals, "Katrina has shot in the most extreme weather conditions with temperatures as hot as a burning furnace. But never once has she complained about it."

Giving an example the friend added, "The Singh is King's song shot in Egypt, it was burning hot that time. The entire cast and crew were perspiring profusely except for Katrina. She looked absolutely chilled out. In fact the hot weather only added to her energies as she went about doing her work calmly. The entire stood surprised."

It is the cold weather that leaves Katrina absolutely cold.

"While shooting for Ajay Prem Ki Ghazab Kahaani in Ooty, Katrina had wrapped herself in layers of blankets. In fact it made quite a funny sight where unit members including Ranbir began teasing her saying, "We now know that most apt gift to give you on any occasion—shawls and sweaters.