I always pack about forty - ahem- 'items of underwear' when I travel to W Africa. Your clothes get soaked in sweat. I felt a bit sorry for the Customs Official at Gatwick on my return who decided to ferret about in my small suitcase. Forty damp XL pants , and several damp other things too. Yeeew.
He probably thought I was a notorious Knicker Smuggler. Hope he washed his hands afterwards!