Just for the record, sometimes when someone says bless your heart, they really do mean bless your heart. It's all in the inflection. My co-worker had to run pick up her daughter from school today because she was throwing up. She called to say she wouldn't be back to work, poor child even threw up in the car (this isn't a young child, she's in high shcool). I said "poor xxxx, bless her heart". I meant bless her heart, she was having a bad day and I felt sorry for the child. Now if someone told me they couldn't get their Caddy started and their Jag was in the shop, I'd say Bless Your Heart! and then I'd be being sarcastic. It's all about context.