4. How this Thermometer Measures Temperature
4a. Understanding Basal Temperatures?
A basal temperature is the normal body temperature of a healthy person
immediately upon awakening after a restful nights sleep. More precisely, it
is the body temperature measured under so-called “basal conditions” (12
hours after eating, after a restful sleep, no exercise, no emotional excitement,
normal room temperature). For optimum accuracy, your basal temperature
should be taken at the same time every morning upon waking. Changes in
basal temperature are related to changes in the female reproductive cycle.
The basal temperature method can be used to help in family planning.
4b. Charting your basal temperature
By charting your basal temperature daily, you can see a pattern and notice
the changes that occur in every ovulation cycle. Keeping a charted record
for at least three months will usually provide the information you need to
determine your approximate day of ovulation during a regular menstrual
cycle. By taking your basal temperature daily and charting it, you can notice
slight changes and patterns. Charting of your basal temperature, in addition
to other information, can help you understand your menstrual cycle and
ovulation. Charting of temperature and prediction of ovulation can be used
to time sexual intercourse during fertile days to aid in increasing the likelihood
of pregnancy.
4c. How to take accurate basal temperatures
To obtain an accurate basal temperature, you must take your temperature
when you first awake in the morning. For best results, this waking
temperature should be taken at the same time each morning. Since any
activity may tend to raise your temperature, do not get out of bed until you
have taken your basal temperature. Postpone going to the bathroom, eating,
smoking or drinking until after taking your temperature. Cold drinks lower
mouth temperature; hot drinks, smoking and exercise cause higher readings.
Using an electric blanket or heating pad can affect your basal temperature. If
you use one, it should be kept at the same setting each night throughout the
time you are taking your basal temperature.
4d. Understanding the Basal Temperature Method
Hormonal changes associated with ovulation produce a slight rise in a
woman’s basal body temperature, (approximately 0.3°C/0.5°F), as well as
other recognizable signs such as changes in cervical mucus. Learning to
record and interpret basal temperature changes is known as the “Basal
Temperature Method.” By monitoring the basal temperature changes,
couples, in conjunction with their physician or family planning counselor,
may be able to determine when ovulation takes place. Monitoring other
symptoms, such as cervical mucus changes, can assist in determining
the fertile days prior to ovulation. When temperature changes are used in
conjunction with other fertility symptoms, such as the cervical mucus, this is
known as the “Sympto-Thermal Method.”
Determination of ovulation can be used to time sexual intercourse during
fertile days to aid in the likelihood of achieving pregnancy. The basal
temperature change used in conjunction with other methods, can also be
