sunscreen is compulsory, use water based moisturizer and prickly heat talc for you oily skin. Talc also adds 5% spf to your actual sunscreen. In spite of that if you have sun burn try to use wet tea bags on sun burns. this will give you relief.
I love to focus on my body skin care all year round but in the summer especially because of the humidity here in the summer. I'm in NY and when it gets hot's it's just sticky and nasty lol. So I keep my bathroom stocked with naturally scented mineral body spray to keep my skin hydrating, soft and smelling tasty! (just ask my husband.....or not!)
I've heard of the tea bag thing, it does work problem with that is I don't like tea, I use milk on my son. He's out in the sun all day cutting grass. as for the slippery makeup have you tried Bareminerals, betcha that won't rum off your face. To cool my skin down in the heat I make up a batch of green tea and sray that on my skin, that tea doesn't smell too bad ( but I still can't stand the taste of it) plus it dissapates quite quickly.
I actually like green tea, and would consider spraying on my face. Kind of funny to drink and wear it. May have to buy more green tea. Never tried bareminerals. I am new to the forum and finding very interesting insights.