For workers who work under direct sunlight:-
1 Drink 3 glasses of plain water before start of work to keep body hydrated.
2. Wear loose light colored cotton made uniforms to absorb sweat, reflect heat & allow air circulation within body.
3. Wear transition lens glasses to protect the eyes from harmful UV rays. Those $5 sunglasses sold at shops do not have UV protection.
4. After every 2 hrs of work, take a 15 - 30 min break in the shade, not under aircon as the sharp drop in temp will harm the body. & drink another 3 glasses of plain water..
Using such measures, productivity may drop but the cost of hospitalization for workers suffering from heatstroke will be far far more expensive
For students, it would be best if school uniforms are made of cotton T shirt material to absorb sweat & wear plain colored Bermuda shorts than long pants for better air circulation, as well as cotton socks & not Polyester, Spandex or Nylon, such which does not absorb sweat.
The climate is changing, & thus measures will be needed in place to protect citizens, as well as personal responsibility for one's health.