“Gutting” also known as “field dressing” is the act of removing the inner guts from the belly of a freshly killed animal, and also letting it bleed out. It is something all experienced hunters realize as a vital procedure. The “guts” are known as “offal” by those who regularly work in slaughter situations, or with hunter game.
The reason field dressing is important is it releases the heat from inside the body. The faster you get the meat cooled down, the less likely it will spoil. If the body is completely closed up, a dead body can take hours to cool down below its normal live temperature, and the inner core is the hottest area of the body, several degrees warmer than skin temperature. Opening the body cavity lets cool air in, and hot air out. Taking the guts out removes unnecessary material that you are not going to use anyway. The intestines carrying fecal matter and any inner fat around the organs can be disposed of.