Of course, adjusting shirts to climatic conditions is not exactly a new idea. Cameroon national team surprised the football world by unveiling a radical sleeveless shirt design in 2002, wearing the gear on official games and even winning African Cup of Nations with them.

However, the FIFA put afterwards a stop to this fashion experiment and banned sleeveless shirt design from the World Cup, forcing Cameroon to revert to a more traditional format. In any case, this experiment remains one of the most inspiring design stories in football and has largely prepared the public for what Hummel is doing now.