A hot left ear could be caused by infection, embarrassment, allergic reaction or red ear syndrome. The symptoms of any of these conditions could include redness, swelling and a burning sensation as though the ear were exposed to a heat source, such as a blow dryer.
The most common cause of a hot left ear is an infection, which could include swimmer's ear or otitis media with effusion. Each of these infections is associated with fluid in the ear and requires treatment from a physician. Left untreated, an ear infection could spread to other areas of the head, including the throat and nose.
Another possibility is an allergic reaction. A contact allergy to a product or chemical, such as detergent, could cause an allergic reaction that includes a burning ear. Insect bites or stings are also possible causes.
Many people blush when they are embarrassed or anxious. Redness and a burning sensation might spread to the chest, throat, cheeks and ears. This is not a cause for concern, as it is the result of blood rushing into the ears.
Red ear syndrome is the least likely cause. There are only 100 confirmed cases in medical history, and its cause is unknown. It is often associated with simultaneous migraines.