For a long time I have had a theory about temperature and productivity of a given civilization. It is definitely true that people living in 100 degree African heat are fully accustomed to it and probably don’t spend their days dreaming of a 15000 BTU air conditioner. However I suspect that this prevalent heat may be a considerable reason why many regions lying within 30 degrees of the equator are considered to be 2nd or 3rd world. In addition to Africa take a look at the Far East, Central America, South America, and the Middle East which lie almost entirely within this sector. These regions lag the world in almost every measure of life expectancy and economic indicators. It was not until the wide spread advent of air conditioning that countries like Saudi Arabia and India began to share in the success previously enjoyed by cooler areas of the world.