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.
Fever, also known as pyrexia and febrile response, is defined as having a temperature above the normal range due to an increase in the body's temperature set-point. There is not a single agreed upon upper limit for normal temperature with sources using values between 37.5 and 38.3 Â°C (99.5 and 100.9 Â°F). The increase in set-point triggers increased muscle contraction and causes a feeling of cold. This results in greater heat production and efforts to conserve heat.