The U.S. is in the grip of a searing heat wave, with temperature warnings and advisories in effect for a large stretch of the central part of the country. States in the south and southwest have been experiencing extreme weather for many months, resulting in a severe drought across a belt of 14 states from Florida to Arizona. Crops and livestock are suffering, as farmers and ranchers struggle to keep them alive. But with no rain in sight and a shaky economy, some are questioning whether this could be a 21st century Dust Bowl.