To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
It reminded me of when I was younger. It is a thermal, as described. It is light in material/weight yet warming worn underneath regular clothing. I even wore it as a shirt under an open sweater. Not really meant to be worn as just a shirt but did the job.