“I was having more and more trouble paying the mortgage,” said Ms. Cox, who is 69. Phoenix, long a retirement destination, has averaged 108 days a year of 100-plus degree temperatures since 1970. Ms. Cox always takes water with her when she leaves the house. “If we could afford it, I’d move back to the California coast,” Ms. Cox said. “I prefer being able to open the windows.”The post Still Dreaming of Retirement in the Sun Belt?