When the seasons change, your base layer expectations change too. In winter it is of course necessary to keep warm, but conversely, summer time calls for cooler clothing. And of course, they have developed sports underwear designed to do just that. Cooling base layer can help you to perform at your highest level when temperatures soar.
Cooling sports underwear is designed with mesh areas to increase breathability for the body, so you do not overheat during a match or training. If you prefer to play with base layer, then cooling sportswear is one of those things you just have to have in your kit bag.