Globally, about seven million hectares of wheat is affected by heat stress. Heat stress is responsible for reducing wheat yield. This problem will be further increased due to global warming. Now-a-days high yielding varieties of wheat can not sustain for longer period due to their sensitivity to fluctuation in changing environment. To overcome this acute problem physiological information is needed to develop appropriate varieties for heat stress condition for better wheat production. Perusal of literature shows that physiological studies on heat tolerance in wheat are limited. In this work different wheat cultivar were evaluated through physiological approaches like membrane thermostability, Seed metabolic efficiency, Stem reserves mobilization, Canopy temperature depression, Sterility, growth and yield performance in relation to heat tolerance. In this book, the findings of this research are discussed in a simple, easy and lucid manner. Therefore, the book should prove to be a valuable resources to the teachers, researchers, postgraduate students in Agriculture, Botany, Crop Physiology and Breeding.