The majority of Adidas heritage products - part of the Originals product line - are manufactured with a suede or leather upper. While these fabrics look good and are hard wearing, they do not allow the foot to breath easily. The only solution Adidas have ever implemented is pressing perforated holes into the leather / suede; perforate is defined as to "pierce and make a hole or holes in". Air can therefore enter in through the holes and allow the foot to cool. Of course, this is a fairly clumsy solution to the problem of foot breathability, but little else can be done with a dense material like leather and suede. Perforated holes tend to be placed in one of two areas on Adidas shoes: the toe area or between the three stripes (shown below). The amount of perforated holes tend to be keep to a minimum: otherwise the 'look' of the shoe is effected and the shoe can 'let in' too much water in rainy weather conditions.
Present day, Adidas rarely implement suede and leather into their performance footwear; shoes designed for sports participation and athletics. They tend to use synthetic materials like "mesh" which is manufactured with a grid of overlaying fabrics that enables small holes to be created throughout the fabric, and creates a far higher degree of breathability in comparison to a suede / leather upper with perforated holes.