Final answer:
To calculate a change in BMR due to temperature changes, you apply the percentage increase or decrease associated with the extent of internal or external body temperature change. For example, a 0.5° C increase in internal temperature raises BMR by about 7%. Additional factors like age, body size, and surface area also play a role in determining BMR changes.
Step-by-step explanation:
To calculate the change in Basal Metabolic Rate (BMR) with a change in temperature, you will need to consider how internal and external temperatures influence BMR. For instance, a rise in internal body temperature increases BMR by approximately 7 percent for every 0.5° C increase. Specifically, an increase in temperature due to fever can raise BMR by 14-15% per degree centigrade. Prolonged exposure to external heat can also lead to an increased BMR, while the body's response to cold results in an elevated BMR to generate the extra heat needed for maintaining internal temperature stability.
Various factors influence BMR, including body temperature, age, sex, race, emotional state, and hormone levels. For age, it's notable that BMR decreases with age, dropping about 2 percent per decade after the age of 20. Additionally, body size and surface area impact BMR rates, with taller and thinner people typically having higher BMRs due to larger body surface areas.
Overall, to calculate the change in BMR resulting from a change in temperature, you would start with the person's current BMR and apply the approximate percentage increase or decrease based on the temperature change they have experienced.