Much of the underdeveloped area of the world is in the tropics. Most tropical countries are underdeveloped. Does the connection between these two facts lie in the obstacles to economic activity created by hot, wet climates? An investigation of this question launched by the Council on Foreign Relations led to this book. Dr. Lee, a physiologist and climatologist, examines the effect of tropical climates on humans, animals, soils and crops, materials, and industrial processes. The result is a clear statement of the present state of knowledge and an indication of the kinds of research still needed, both to appraise the obstacles created by tropical climates and to assess the means of overcoming them.