This is a common question presented in the fan business and a common misconception. Lasko fans are designed as air movers. They move the air in the room to help prevent stagnated air and provide a a "breeze effect" but they will simply move the room temperature air around. Lasko fans do not have cooling mechanisms inside that allow them to act as a portable air conditioner. In other words, there is nothing inside of the fans that will cool the air.
A fan, if placed in front of an air conditioning unit can help to move the cold air from the A/C throughout the room at a faster rate than the fan inside of the A/C unit can. This can help to speed up the cooling of the room.