Each bean contains 0.8 - 2.5 % caffeine. For your information in an average cup of coffee you have 75mg caffeine. One cup of coffee contains around 25 coffee beans, and you are not getting the full coffee bean in coffee, so the caffeine can add up if you eat a lot.
The reason why temperature effects muscles is because of the numerous atoms in the body that react to temperature. When the air, or body temperature is colder the atoms tend to stay closer together, causing less movement...when it is hot, the atoms (molecules) move around more, causing more range of motion. It also allows blood to flow more easily when it is warm than cold.
This is homeostasis in the skeletal muscles. Your body must maintain the average temperature (37Â°) and when your body shivers it is because your body has dropped below that temperature. For your body to get back up to that temperature it uses homeostasis of the skeletal muscles by generating heat to warm you up.