Not all sweat is created equally. In fact there are two distinct types of sweat, created by two different kinds of glands. The eccrine glands, which can be found on the hands, feet and forehead, produce sweat which is 99% water and therefore largely inoffensive on the nose. The apocrine glands, however, can be found around the groin and the pits and are largely responsible for your unique brand of BO.
Depending on the kind of sticky situation you find yourself in, one of these two kinds of glands will start working overtime. Here are some classic sweaty scenarios: