What Causes Dryness In Skin At Cheeks And Forehead?

hello doctor my problem is dat in last summer due to extreme heat my skin started drying in some areas like cheeks n forehead and, started peeling out in small proportions and then because i mishandled it dark spots began to develop specially there is a small dark patch on my skin and recently some small patches have developed on my forehead how shall i get rid of these marks.