Stay indoors as much as possible between 10 am and 3 pm. At these times the sun reaches its peak and you are more likely to overheat. Drink plenty of fluids throughout the day. And by fluids I don't mean Caffeinated Sodas. Caffeine dehydrates you.
Water is by far the best liquid to choose.
It gets into your system faster than other drinks. Remember to use your sunscreen. Please remember to use the highest degree of coverage. Also remember that some sunscreens may not allow you to burn but some do allow the damaging light in that is known to cause skin cancer. Get to a place that is airconditioned.