As a registered dietitian nutritionist, and mother of little ones, food safety is of the upmost importance to me (and it should be to you too)! To avoid the possibility of pathogens growing in your food, it's important that perishable foods, like the dairy products used in this recipe, remain at room temperature for no greater than two hours. For this recipe, that means your hot dip will likely exceed the danger zone threshold (140 degrees F) when cooking, and then be set out for your guests to enjoy. Since it will be set out warm, this likely gives your dip a little over two hours to sit out. If it makes it this long (doubtful!), be sure to cover it up, and place in the refrigerator so that it's temperature can drop.