It could mean many things when the palms of your hands turn very red and very hot suddenly. The cause could be high blood pressure, poor blood circulation, or you could just have a fever. There is something called Erythromelalgia which is a rare disease that causes red, hot hands and feet. Go to your doctor and tell him or her your symptoms. Get the doctor to check you out and get every test that the doctor suggests. I hope everything works out for the best!