There is a medical condition called gustatory rhinitis that causes a runny nose and/or sneezing after eating hot or spicy foods. The foods can be in solid or liquid form. It is a type of nonallergic rhinitis, where your nose gets inflamed but not because of a specific allergy. Gustatory rhinitis can cause several symptoms including sneezing, stuffy nose, runny nose, post-nasal drip, and cough. This disease is most likely caused by the stimulation of sensory nerve endings located in the nose and upper digestive tract. Avoidance of the implicated foods is the main treatment option. In your case, it could be due to the actual temperature of your coffee or something you are putting in your coffee.