I'm otherwise healthy and very active, but been having a pins-and-needles sensation on the left side of my face and down my left arm a few times a day, lasting 1-10 mins. history of neurological conditions on my mum's side -- could this be serious?

There are a variety of nerves running along the sides of your head/face. Any burning, cold, tingling, painful jolt, or crawling sensation could be the result of improper stimulation of these nerves = parasthesia. If this is a recurring sensation or you have strange sensations in multiple areas, it might be time to see a neurologist. They can do nerve testing and determine the underlying cause.

Agree with visit to neurologist but do not worry as this appears paroxysmal and not progressive. Could be merely a migraine equivalent especially if history of headaches