One ear blood red no pain just feels hot?

Possible infection. Recent piercings or injury to ear? Cartilage may be infected & require antibiotics and/or incision & drainage. Other possibility is hematoma beneath the skin from injury; drainage by ENT or fp may be needed for relief of pain & to prevent complications. Cool compresses may decrease swelling as temporary measure until doctor is seen.
Red earlobe. If it is only one earlobe red and warm this could be infected. Go to dr. Otherwise your earlobe could get deformed if not treated early. Besides! you need to clarify the diagnosis.