 cotton fields and the brutal heat you know it didn't bother them because they're from africa and their skulls were thicker or they had a different kind of adaptation to heat than you know the largely white plantation owners and you know one of the things i really underscore in this book is that yes there are differences in how different people deal with heat if you're older if you have heart conditions if you're a diabetic if you have circulatory problems if you're a pregnant woman