Why does a ball, carried out of a room outside in winter, become weakly inflated?

For the gas in the middle of the ball, Charles’s gas law is valid. For a constant gas mass, with its volume constant V = const, the ratio of the gas pressure P to the absolute temperature T remains unchanged: P / T = const. Since the temperature outside T2 is lower than that in the room T1, the gas pressure inside the ball on the street P2 should be less than in the room P1. P1 / T1 = P2 / T2. T1 <T2, then P1 <P2.