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.
And the temperature stays at 98.6F. What these chemicals from the white blood cells do, is they increase the thermostat. So the brain now has a set point of 101 F. But the body is still 98.6 F. So the heater kicks on. You get shivers, moving of muscles fast makes heat. You feel cold and you get under covers to get warm.