Basic observations
Barbara Smith, Linda Field in Nursing Care, 2019
Body temperature reflects the balance between heat gain and heat loss from the body and is measured in units called degrees. There are two kinds of body temperature: core temperature and surface temperature. The core temperature is the temperature of the deep tissues of the body, such as in the abdominal, cranial and pelvic cavities and is also located in the blood supplying organs such as the brain (McCallum and Higgins, 2012). The core temperature remains relatively constant in a healthy person, within the range of 36–37.6 °C, is acceptable in clinical practice (Childs, 2011). The surface temperature, sometimes called the peripheral temperature (McCallum and Higgins, 2012), refers to the temperature of the skin, subcutaneous tissue and fat. The surface temperature fluctuates in response to the environment; consequently, there can be a great variation in recordings between core temperature and surface body temperature.
Basic Thermal Physiology: What Processes Lead to the Temperature Distribution on the Skin Surface
Kurt Ammer, Francis Ring in The Thermal Human Body, 2019
Deep body temperature was the main interest of early clinical thermometry as a relationship between fever and elevated deep body temperature was established by the mid of the 19th century. The fact that deep body is stable in different climatic conditions that result in various skin temperatures was known for a long time. However, the German physiologist J. Aschoff was one of the first who used consequently the term “core temperature”. He based his differentiation between core and shell on the observation that at rest most of metabolic heat is produced in inner organs located inside the chest and abdomen. In other words, core temperature represents the intensity of heat stored in the inner organs. Changes in core temperature are related to increase or decrease of heat content that in turn affects the temperature gradient from the core to the surface.
Protocol for Standardized Data Collection in Humans
U. Snekhalatha, K. Palani Thanaraj, Kurt Ammer in Artificial Intelligence-Based Infrared Thermal Image Processing and Its Applications, 2023
Pascoe and Fisher investigated the change in face temperature at sites considered to provide temperature readings that may be used as a substitute for core temperature (Pascoe and Fisher, 2009). Twenty-two college-aged, healthy participants (11 males, 11 females) performed six trials at three ambient temperatures (15.5, 21.1, and 26.6°C) and either 35% or 70% humidity. Participants wore similar clothing in all trials. The trials were performed at the same time each day with participants being equilibrated for at least 15 minutes before temperature measurements were obtained. There was a separation of at least 24 hours between each trial. Core temperature was measured at the rectum, in the esophagus, oral, and at the tympanic membrane. The axilla, the forehead, the temple, and the inner canthi of the eyes were the sites of surface measurements.
The effects of combined exposure to noise and heat on human salivary cortisol and blood pressure
Published in International Journal of Occupational Safety and Ergonomics, 2021
Mohammad Javad Jafari, Reza Khosrowabadi, Soheila Khodakarim, Fariba Khodagholi, Farough Mohammadian
Heat stress is another major occupational and environmental stressor affecting human health [5]. In a healthy individual, the body core temperature is kept at 36–37 °C. Thus, when the core temperature of the human body rises, the thermoregulatory system reacts and causes the body to lose heat [6]. When the thermoregulatory system is unable to handle the heat stress, the risk of heat-related ailments increases. According to Brown’s [7] report, more than 200 deaths and 1500 work days were lost in the USA in response to heat exposure in the workplace from 1999 to 2003. Different studies, including Horfarasat et al. [8] and Follenius et al. [9], have proven that heat stress leads to physiological changes in the human body which are called ‘heat strain’. Wilson et al. [10] and Melesse et al. [11] suggested that exposure to excessive heat can significantly raise the body core temperature, heart rate and vascular resistance in the brain. There have also been reports of changes in certain metabolic hormones such as cortisol, thyroid and norepinephrine under heat stress conditions.
Hemodynamic response to thermal stress varies with sex and age: a murine MRI study
Published in International Journal of Hyperthermia, 2022
A. Colleen Crouch, Aditi Batra, Joan M. Greve
Core temperature impacts human performance and health. Humans maintain core temperature via the process of thermoregulation [1–5]. Thermoregulation is affected by changes in: convective heat transfer from skin to environment, autonomic nervous system and metabolic processes, and cardiovascular (CV) system. The CV system influences heat transfer via forced convection and conduction by changes in blood distribution (conduction and convection), proximity of vessels/tissues (conduction), and blood velocity (convection) [6]. Cardiac output, vessel size, blood flow velocity, and pressure all influence these parameters. In addition, sex and age influence the body’s ability to perceive and respond to changes in temperature [5,7–10] and affect the function of the CV system [11–13]. Therefore, the effect of body temperature on each parameter must be quantified, ideally across age and sex, to fully understand the CV system’s role in thermoregulation.
Cross-sectional area of the murine aorta linearly increases with increasing core body temperature
Published in International Journal of Hyperthermia, 2018
A. Colleen Crouch, Adam B. Manders, Amos A. Cao, Ulrich M. Scheven, Joan M. Greve
Core temperature impacts human health and performance [1–5]. Humans maintain core temperature via the process of thermoregulation [6]. The body utilises two pathways to achieve this homeostasis. The passive system includes heat conduction through tissues and convective heat transfer via the cardiovascular (CV) system (forced) and from the skin’s surface to the environment (natural). The active system includes changes in cardiac output (CO), vasodilation or constriction, sweating, and shivering [7]. The CV system plays an essential role in both systems. However, it remains unclear how the allocation of blood in various compartments (e.g. core, fat, muscle and skin) changes with temperature [8,9]. Early work suggested skin was the primary compartment in which increases in blood flow occurred when core temperature was increased [10], but it has also been demonstrated that there are increases to the muscle with increased temperature [11–15]. Sex and age not only influence the body’s ability to perceive and respond to changes in temperature [5,16–20], they also affect the function of the CV system [21–24]. Therefore, to fully understand the CV system’s role in the complex process of thermoregulation, blood distribution (influenced by CO, vessel size, blood flow velocity and pressure) must be quantified, ideally across sex and age.
Related Knowledge Centers
- Chemical Reaction
- Circadian Rhythm
- Superficial Temporal Artery
- Thermoregulation
- Rectum
- Homeostasis
- Body
- Thermoregulation In Humans
- Physical Examination
- Medical Thermometer