The objective of the present edited book is to encompass studies from both developed and developing countries of Asia, Africa Europe, and Americas, to understand and present a comparative scenario of the climate change and other environmental determinants of health and disease in geographically diversified countries. Environment and health perspective dates back to Hippocrates treatise written 400 B.C.E. In his book On Airs, Waters and Places, Hippocrates described diseases as associated with environmental conditions, "Whoever wishes to investigate medicine properly, should proceed thus: in the first place to consider the seasons of the year, and what effects each of them produces for they are not at all alike, but differ much from themselves in regard to their changes. Then the winds, the hot and the cold, especially such as are common to all countries, and then such as are peculiar to each locality. We must also consider the qualities of the waters, for as they differ fromone another in taste and weight, so also do they differ much in their qualities. In the same manner, when one comes into a city to which he is a stranger, he ought to consider its situation, how it lies as to the winds and the rising of the sun; for its influence is not the same whether it lies to the north or the south, to the rising or to the setting sun".
There has been a greater emphasis in the last four decades on understanding environmental factors which affect human health, after United Nations established Intergovernmental Panel on Climate Change (IPCC) in 1988 aimed at to evaluate research on changing environmental condition, particularly climate change and its impacts on human wellbeing, including human health, as consequences of extreme heat waves conditions, sea level rise, forced migration, air pollution, droughts, and wildfires. From these studies, risk levels of vulnerable populations and regions can be assessed and level of resilience of healthcare infrastructure that may be used in environmental health policy and equity of these countries.