This text investigates how human physiological mechanisms adapt to non-idealized conditions, specifically focusing on the impacts of aging, environmental stress, and varying life stages. The authors, R. M. Case and J. M. Waterhouse, utilize their academic backgrounds in physiological sciences to provide a comprehensive update to their previous work, incorporating expanded data on human development and environmental interaction. The book argues that studying these extreme or variable conditions is necessary to achieve a complete understanding of standard physiological processes.

Experts recognize this volume as a specialized supplement to standard medical curricula, valued for its focus on variables often omitted in general textbooks. Readers frequently note the academic density of the prose, which is tailored for students and professionals seeking a deeper understanding of physiological adaptation.