Southerners: is "bless your heart" always ironic?

I’m from Michigan, and I didn’t grow up hearing the expression, “bless your heart”, but I’ve picked it up somehow. I use it non-ironically when someone does something thoughtful. But I gather the expression is used ironically in the South, as in “He just can’t seem to hold onto a job, bless his heart” (in which “bless his heart” is used as a euphemism for the plainly derogative expressions that a Northerner might use in this context, such as “the loser”). I’m wondering if Southerners ever use this expression simply to express its surface meaning or if it is always used in this euphemistic/ironic way.