Pretty much what other users said:

• remember to drink (water is the best but if you feel fatigued from the heat there are supplements that you can add to the water, ask your pharmacist)
• natural fibers clothes like cotton or linen are better that synthetic ones
• you can even buy a little fan to put on your desk, they’re powered through a usb so you don’t need a socket, just your pc
• if you’re outside in the sun don’t forget a hat
• eat a lot of fruit and vegetables, they’re fresh and have all the good vitamins and plenty of water Hope this helps! From the sunny Italy