Numbness in left arm tingling in fingers and my thumbs get really cold?

Not sure: these complaints could be from any number of issues ranging from problems in your neck to your shoulder elbow or wrist if they persist you should seek evaluation with someone who can perform a thorough physical examination

?nerve compression: Most likely cause is carpal tunnel syndrome due to nerve compression at wrist, but also, consider nerve compression at elbow. Your doctor might get EMG test to confirm location and extent.

See below: This may be coming coming from a pinched nerve in your neck. See your physician for a full workup