(2) A person whose normal body temperature is below average (such as
97.6 F) is said to have a "low-normal" body temperature.
b. Menstrual Cycle Affects Body Temperature. A woman's body temperature
drops slightly before ovulation, rises about 1 F above normal during ovulation, and then
returns to her normal level.
c. Pregnancy Affects Body Temperature. During pregnancy, a woman's body
temperature stays above her regular normal temperature.
d. Physical Activity Affects Body Temperature. When a person exercises or
does hard work, his muscles change stored energy supplies in the body (mainly glucose
and fat) into usable energy. When the body's muscles change stored energy into
usable energy, heat is given off. This is why you can warm up in cold weather by doing
e. Age Affects Body Temperature.
(1) A newborn baby has some difficulty in adjusting his body temperature.
His temperature may be slightly high one time and slightly low the next. By the time, the
baby is one year old, the parts of his body that control his body temperature are fully
developed and his normal body temperature has been established.
(2) An elderly person will usually have a low-normal body temperature. The
lower body temperature is caused by changes within his body and by a decrease in
f. Weather Affects Body Temperature. When a person's body is exposed to
hot weather, his body temperature rises. When a person's body is exposed to cold
weather, his body temperature drops. In the cold environment the body loses heat in
the following five ways.
(1) Conduction. Conduction is the direct transfer of heat from a part of the
body to a colder object. For example, when a warm hand touches cold metal or ice, or
when a person's hand is immersed in water with a temperature below his body
temperature. Heat passes directly from the body to the colder object.
(2) Convection. Convection occurs when heat is transferred to circulating
air, as when cool air moves across the surface of a person's body. A person who is
standing outside in windy winter weather and who is wearing lightweight clothing is
losing heat to the environment mostly by convection.