Related Concept Videos
01:14Mechanisms of Heat Transfer I
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
01:19Mechanism of heat transfer
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
01:14Mechanisms of Heat Transfer
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant heat.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant heat.
01:20Mechanisms of Heat Transfer II
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
01:16Physical Principles Governing Gas Exchange
Gas behavior plays a vital role in understanding bodily processes such as external and internal respiration. External respiration involves the diffusion of oxygen into the blood and carbon dioxide out of it in the lungs. In contrast, internal respiration happens in body tissues, where these gases move in opposite directions.
Gas Laws Governing Respiration
The behavior of gases is guided by Dalton's Law of partial pressures and Henry's Law.
Dalton's Law asserts that the total pressure exerted by...
Gas Laws Governing Respiration
The behavior of gases is guided by Dalton's Law of partial pressures and Henry's Law.
Dalton's Law asserts that the total pressure exerted by...
01:18Adiabatic Processes for an Ideal Gas
When an ideal gas is compressed adiabatically, that is, without adding heat, work is done on it, and its temperature increases. In an adiabatic expansion, the gas does work, and its temperature drops. Adiabatic compressions actually occur in the cylinders of a car, where the compressions of the gas-air mixture take place so quickly that there is no time for the mixture to exchange heat with its environment. Nevertheless, because work is done on the mixture during the compression, its...
You might also read
Related Articles
Articles linked to this work by shared authors, journal, and citation graph.
Sort by
Same author
Ventilatory efficiency during weaning from venovenous extracorporeal membrane oxygenation.
American journal of respiratory and critical care medicine·2026
Same author
Albumin Replacement Therapy in Septic Shock: A Randomized Clinical Trial.
JAMA network open·2026
Same author
Albumin kinetics, intravascular fluid volume, and respiratory function in pigs ventilated at different levels of mechanical power following crystalloid vs. albumin infusion.
Intensive care medicine experimental·2026
Related Experiment Video
Updated: Jun 20, 2026
13:27
Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface
Published on: June 8, 2015
Forced-air warming: technology, physical background and practical aspects.
Anselm Bräuer1, Michael Quintel
1Department of Anesthesiology, Emergency and Intensive Care Medicine, University of Göttingen, Göttingen, Germany. abraeue@gwdg.de
Current Opinion in Anaesthesiology
|September 8, 2009
Summary
Forced-air warming systems are crucial for patient temperature management. Blanket design significantly impacts heat distribution and efficacy, with lower temperature differences indicating better performance for preventing hypothermia.
More Related Videos
10:03Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel
Published on: October 5, 2018
06:28Fabric Moisture Uniform Control to Study the Influence of Air Impingement Parameters on Fabric Drying Characteristics
Published on: August 19, 2019
Area of Science:
- Medical Devices
- Thermoregulation
- Biomedical Engineering
Background:
- Increasing availability of forced-air warming devices.
- Limited research on the physical principles of these devices.
- Difficulty in selecting optimal devices due to lack of data.
Purpose of the Study:
- Investigate the physical background of forced-air warming devices.
- Identify factors influencing device efficacy.
- Provide guidance for selecting suitable devices.
Main Methods:
- Analysis of heat flow from power units.
- Evaluation of heat transfer from blankets to the body.
- Assessment of heat distribution homogeneity within blankets.
Main Results:
- Heat flow is dependent on nozzle air temperature and airflow.
- Heat transfer relies on heat exchange coefficient, temperature gradient, and coverage area.
- Homogeneity of heat distribution is critical; lower temperature differences signify better blanket performance.
Conclusions:
- Forced-air warming system efficacy is primarily determined by blanket design.
- Low temperature difference between highest and lowest blanket temperatures indicates a high-performing blanket.
- Prewarming patients for 30-60 minutes and using the largest possible blanket during surgery are recommended to prevent hypothermia.