Upper limb movement

People tend to cross their arms. Why do  they do it ? Because it is a sign their limbic brain shows a kind of emotion . That emotion comes when something they don't agree with or discomfort with the person or the place . They do it it because of pressure or tension which is causing them to do cross arms. 

Crossing arms tightly shows discomfort and tension . It must be noted when you talk to somebody . If you soothe them some how in that situation they tend to loosen up their arms but not change from the position sometimes. 

Women tend to cross their arms in the belly and show up their upper body . 

Men tend to cross their arms in their chest .

Sometime men do other things like adjusting their time or collar for a long period of time that refers to discomfort to the situation.

When this type of discomfort happens , the blood in their skin are pushed toward the muscles to soothe them , give them comfort and lower the pressure. Which causes a cooling effect on the skin .