Ok so maybe someone can enlighten me. I was under the impression that deflecting heat is something that wasn't too hard to do (flat roofs, narrow street closed

Ok so maybe someone can enlighten me. I was under the impression that deflecting heat is something that wasn't too hard to do (flat roofs, narrow street closed windows, more shades, etc.). Am I wrong in believing that people can find some low tech inexpensive solutions to the problem of overheating?