Warmth in the injured finger may be a normal phenomenon, or it may be caused by infection, nerve damage and other factors. 1. Normal phenomenon: injured fingers have normal blood vessel congestion due to tissue contusion, blood vessel congestion leads to an increase in local blood flow, which can lead to an increase in the temperature of the finger, causing the finger to heat up. 2. Infection: If there is an open wound on the injured finger, it is easy to breed bacteria, resulting in wound infection, local inflammation, causing redness, swelling and heat pain in the finger. 3. Nerve damage: If the injured finger nerve damage, may lead to nerve dysfunction, the patient will feel the injured finger fever. Patients with fever in the injured finger should go to the hospital in a timely manner to improve the examination and give targeted treatment after the cause is clear.