basically, exactly what it is called. hugging a person while either you, or you and the other person is sweaty. its a good thing, considering most people consider sweat to be gross ( which I dont, unless its on a nasty, unhygenic person ) ..so if someone gives you a sweat hug, it means they like you, enough to get your sweat all over them. O.O yep.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.