I don't wear Vests, but my husband does.
Last year, I bought 2 of this for my sister and Brother who have a home in the cool mountains of Borneo.
I was traveling by budget airline and didn't buy any luggage allowance. I had my books to meet the family, so I wore 2 vests and my winter jacket. Told this story to my adult ESOL students.
By the time I was waiting in the holding pen in the airport, I was baking. They laughed.