There are a few different options out there, but all of them work by removing the moisture from your balls. When you’re sitting around in a pair of shorts or even a wet bathing suit, they can sweat and if it’s hot enough, that sweat will eventually make its way down between your thighs where there is no air to help dry it out. This causes an uncomfortable amount of heat to build up on the outside of your testicles.
The best solution for this so far has been some form of absorbent underwear like boxer briefs but these are not always practical during certain exercises (lifting weights). The other option has been Bikinis that have built-in towels designed specifically for sweaty skin on the outside of your scrotum area. These things do exist but I haven’t found any direct reviews on how well they work yet… more research needed! Hopefully one day we will see something similar come along with better performance than simply providing some sort of temporary relief while wearing it…but until then, DIY solutions remain our best bet at drying out our testes!