Beauty advice needed to survive a hot-weather, outdoor wedding

I’m going to a wedding in AZ in mid-May. Two concerns I need advice on:

1) I want to make sure my makeup holds up despite the combination of the heat and my oily skin (t-zone and chin mostly).

2) Body makeup in the heat seems like a bad idea for my dress but I want to lessen the appearance of some scars/discoloration on my arms and back and have a hydrated, glowy look.

What products/techniques would you recommend to look my best? Thank you in advance.