First, figure out which side of the house your room is on. Facing North it gets no sun in through the window. East gets the morning sun till about noon, South gets the afternoon sun, West gets the evening sun.
South is the HOTTEST. Facing East is the second hottest, West is the third hottest and North is the coldest. That is if there is NO BUILDINGS SHADING YOU.
Time your window openings for fresh air according to when you have no sun(shady) and blow air into the room at that time. As soon as the sun shows up. Close the window and remove the fan. If the window has a curtain, now close it...white side out facing the sun and pretty side of curtain facing into the room. If the neighbors do not like the look of the backside of the curtain, TOUGH.
. This is what you got to do DAILY.
. iF ON THE SOUTH SIDE YOU only can open the window in the evening...when it is shady.