Heat: Mechanisms of Heat Gain and Loss in the Human Body

Heat 1
ASSIGNMENT 2 – HEAT
By (Name)
Course
Professor’s name
University name
City, State
Date of submission

Heat 2
With diagrams describe the ways that the human body gains or loses heat to its
environment. Explain how these mechanisms work.
Body metabolism is responsible for continuous generation of heat in human beings, with one on
average outputting 10 W but with a fluctuation that goes along with activity. Thermal regulation
is therefore important to continuously rid the body of this heat to the environment (Houdas &
Ring, 2013).
Heat in the human body is lost through the following processes;
● Evaporation
● Convection

Heat 3
● Radiation
● Conduction
Heat loss by evaporation
Exposure to high temperatures especially after an intensive activity leads to sweating which is a
natural process of heat reduction in the human body (Houdas & Ring, 2013). Evaporation takes
place on the skin surface where water from body cells heats up and the energy transferred to the
external environment.
Heat loss/gain by radiation
Radiation does not need a medium to occur. Transfer of heat is by electromagnetic waves. Heat
felt by human beings from the sun is a good example of heat transfer by radiation.
Heat gain/loss by conduction
Heat transfer by conduction involves two or more solid bodies with unequal temperatures being
in contact. Heat is transferred until the two bodies achieve equilibrium temperature. So heat can
be conducted from a warm object to one’s body or vice versa.
Heat loss by convection
The medium for this mode of heat transfer is fluids. Heat from the human body is conserved by
clothing which traps the warm air around the skin (Sherwood, 2015). Wind blowing across ones
skin replaces the warm air around the skin with cold air through convection.

Heat 4
2. For an uninsulated brick veneer house in Sydney in winter describe the main paths of
heat loss to the outside air
Buildings just like human beings also experience heat transfer with the environment. In Sydney
for example, a brick house without insulation would have high levels of heat losses going by
very low environmental temperatures (Law & Dewsbury, 2018). The rate of heat transfer
depends on the temperature difference between the building and its surrounding.
Heat in buildings is lost through;
 The ceiling
 The walls
 The glazing
 The floor