Sunscreen is your friend
You’ll constantly encounter sun exposure during this season, so sunscreen is essentially your ally. Always use a sunscreen SPF at least 25+. Apply 20 minutes before you go into the sun to allow your skin time to absorb it. Re-apply as needed throughout the day, particularly after a swim. If not able to tolerate due to oiliness, mix it in a little calamine lotion or dab it with a talc. Just make sure that the product contains nourishing ingredients.
Apply cool compresses to sunburned skin to help reduce the area temperature. Never exfoliate or use a mask on sunburned skin until the area has healed, and be sure to go light on your favorite perfume until the burn is gone.
Don't skip the moisturizer
Just because you may have oily skin in the summer doesn't mean you can skip the moisturizer. Your skin will only act up and produce more oil if you do. Though for this season, you can switch to a more lightweight formula. Sure, you can drop the moisturizer in the morning to make way for the SPF and stop you from looking like a greasy mess even before you actually step outside of the house. But definitely apply some moisture before going to bed.
Constant hydration and nutrients
Drink plenty of water to avoid dehydration and heat stroke. Remember water is the number one aid to skin care during this season. Another thing: eat lots of fresh fruits and vegetables (those that are rich in beta-carotene - carrots, spinach, lettuce, tomatoes, broccoli, watermelon, etc.) so your body gets replenished from all the activities under the heat.