Metabolic rate in the context of "Oligotrophic"

Thermal comfort is the condition of mind that expresses subjective satisfaction with the thermal environment. The human body can be viewed as a heat engine where food is the input energy. The human body will release excess heat into the environment, so the body can continue to operate. The heat transfer is proportional to temperature difference. In cold environments, the body loses more heat to the environment and in hot environments the body does not release enough heat. Both the hot and cold scenarios lead to discomfort. Maintaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the important goals of HVAC (heating, ventilation, and air conditioning) design engineers.

Thermal neutrality is maintained when the heat generated by human metabolism is allowed to dissipate, thus maintaining thermal equilibrium with the surroundings. The main factors that influence thermal neutrality are those that determine heat gain and loss, namely metabolic rate, clothing insulation, air temperature, mean radiant temperature, air speed and relative humidity. Psychological parameters, such as individual expectations, and physiological parameters also affect thermal neutrality. Neutral temperature is the temperature that can lead to thermal neutrality and it may vary greatly between individuals and depending on factors such as activity level, clothing, and humidity. People are highly sensitive to even small differences in environmental temperature. At 24 °C (75.2 °F), a difference of 0.38 °C (0.684 °F) can be detected between the temperature of two rooms.

Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is most commonly used to pass through winter months – called overwintering.

Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and use similar mechanisms. The equivalent during the summer months is aestivation.

The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter of water by one degree Celsius (or one kelvin). The small calorie or gram calorie is defined as the amount of heat needed to cause the same increase in one milliliter of water. Thus, 1 large calorie is equal to 1,000 small calories.

In nutrition and food science, the term calorie and the symbol cal may refer to the large unit or to the small unit in different regions of the world. It is generally used in publications and package labels to express the energy value of foods in per serving or per weight, recommended dietary caloric intake, metabolic rates, etc. Some authors recommend the spelling Calorie and the symbol Cal (both with a capital C) if the large calorie is meant, to avoid confusion; however, this convention is often ignored.

Thyroxine, also known as T₄, is a hormone produced by the thyroid gland. It is the primary form of thyroid hormone found in the blood and acts as a prohormone of the more active thyroid hormone, triiodothyronine (T₃). Thyroxine and its active metabolites are essential for regulating metabolic rate, supporting heart and muscle function, promoting brain development, and maintaining bone health.

Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time a hibernator spends at low body temperature, lasting days to weeks, or it can refer to a period of low body temperature and metabolism lasting less than 24 hours.

The word comes from the early 13th century, originating from the Latin, torpor, to be numb or sluggish.