My pinky finger is numb.  I work as a welder and didn’t wear my gloves while grinding yesterday.  Should I be concerned?   

You possibly could be having ulnar nerve compression due to trauma. Vibrations from grinding can be traumatic to nerves and can cause swelling, which can then cause swelling.  This swelling can cause a brief compression of the nerve as it courses through a small tunnel in your wrist.  It is wise to use gloves to decrease vibration and best if you rest it all together.