I have a white wicking Columbia long sleeve “hoodie” that I wear in the sun. It’s much cooler and keeps me from getting sun baked.Landscapers here all wear hoodies in blistering summer heat. I once asked my brother in Louisiana, who has experience with manual labor in crazy high humidity.
His response? I'll paraphrase:
"Clothes that are saturated with sweat behave very differently from one that are dry. If you just assume your shirt will be soaked, you dress differently. It's not the hoodie, it's the hoodie OVER the shirt underneath. The hoodie gives you sun protection and the bulky loose sweatshirt lets air circulate and evaporates sweat from the saturated shirt underneath."
Basically, a hoodie is not super insulating if there's breeze or a saturated wet shirt under it.
Lots of outdoor workers here wear long sleeves for same reason.
A traditional beanie on the other hand I don’t think would help?