“Review of obagi system (including retin-a)”

Seeking help:

I am wondering if heat can cause Melasma and hyperpigmentation to return. I did 18 weeks of Obagi with great results. My melasma and sun spots were all but gone. I wear sunscreen and hats almost all the time when I'm outdoors but I feel as if my spots are starting to return. So, I'm wondering what type of sunblock is best for being in the pool with the kids, and/or am I fighting a losing battle because getting my face hot (while outside or at the gym) is actually causing my spots to return.