is classified as a parasthesia in medical terms. There are many causes of this sensation--and some require medical attention. I recommend seeing your primary care doctor
who could both evaluate your symptoms and potentially treat this symptom.
In general a parasthesia is a sign of a nerve problem. There are a few a ways that nerves can get damaged. One of the most common is if the nerve is getting pinched. For the nerves in the hands--the three places that the nerves are most commonly pinched are (a) in the neck which is often associated with neck pain (b) in the elbow--this often is the ulnar nerve and will classically cause tingling in the pinky and fourth finger and (c) the carpal tunnel in the wrist. This is the most common and classically pinches the radial nerve and causes tingling in the thumb, pointer and middle finger. Carpal tunnel syndrome
is the most common in young women.
There are other diseases that can globally damage the nerves. These include diabetes, vitamin B12 deficiency, hypothyroidism, syphilis, Lyme disease and amyloidosis. These often effect the nerves in the feet before the hands--but this is not always true.
There is no obvious correlation between a nerve problem and sunlight or temperature. That being said, nerve problems are notoriously unique and difficult to characterize.
I would see your doctor. There are various causes of the pins and needles, some of which should be ruled out lest they cause serious harm. The most common, carpal tunnel, can be treated. Good Luck.