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 increases the metabolic rate about 7% for each degree rise in body temp. How much a person's muscles as relaxed affects the amount of energy used. The less relaxed the muscles are, the greater the metabolic rate. Emotional strain can cause increased tension and thus increase metabolic rate. That being said, do relax and get adequate sleep.