ORIGINAL: Flairball

I hunted today, and will be going out again in the morning. Should I pull the bullet, and remove the shot charge, or can I leave the gun as is tonight? My father always says to leave the gun in the car so the temperature change won't affect the shot charge, but I live in the city, and hunt a suburban wood lot 15 minutes away, so i don't feel comfortable leaving the gun in the car. Opinions please?