The cooling scarfs or a piece of light weight cotton cloth ( not a towel) wetted with water around the neck makes a big difference. I worked construction for 32 years, the evaporative effect helps keep you cool as the cloth is in contact with your neck and the carotid arteries pick that up and make a noticeable difference. You can rewet it anytime with cool water. My shirt will get wet but that just adds more cooling affect. And (as mentioned) wear a hat the combination of these two items really helps. This may not make much of a fashion statement but it does go a long way toward comfort on a hot day. Did this often when working to get through days when no other relief was available in direct all day sun.
Just be careful of going in and out of air conditioning too often or too fast, or you may get nauseous. If you can, "acclimate" yourself by lowering the a/c in your home so your body is more used to warmer temperatures, and don't just walk into and out of a/c regularly. Maybe go sit in the shade somewhere and have a cool water then keep going, or hang out in an air conditioned spot for a few minutes then head back out for a while. I learned the nauseous part from experience!
I used to do that, but not by choice. My classroom wasn't air-conditioned and sometimes I would walk into it in the morning and the temperature would be 90 degrees in the morning. It did get me prepared for Florida weather.
