Body Temperature and Vital Signs Study Notes

Factors Influencing Body Temperature

  • Average Body Temperature: Varies by individual and time of day.

    • Healthy adults: 97.7° to 99.5°F (36.5° to 37.5°C)

    • Average daily temperature: 98.6°F (37°C)

    • Some studies suggest a decrease; current average: 97.8°F (36.6°C)

  • Body temperature is lowest in the morning and highest in the late afternoon.

Factors Affecting Body Temperature

  • Age:

    • Infants and young children experience rapid fluctuations in temperature due to environmental conditions.

    • Aging adults lose thermoregulation capacity due to reduced subcutaneous fat.

  • Stress and Physical Activity:

    • Exercise and emotional stress can elevate temperature through increased metabolic rates.

  • Gender:

    • Hormonal changes in women can cause fluctuations in core body temperature throughout the menstrual cycle.

  • External Factors:

    • Activities such as smoking, drinking hot fluids, and chewing gum can temporarily raise oral temperature.

    • Cold weather typically reduces body temperature; hot weather increases it.

Fever and Body Response

  • Definition of Fever: Body temperature rises in response to infection (bacterial or viral), often linked to illness.

  • Physiological Response:

    • Fever can be a protective mechanism, inhibiting the growth of pathogens.

    • Constriction of superficial blood vessels leads to chills and goosebumps, increasing internal heat.

    • When heat production exceeds loss, temperature rises above normal.

    • Conversely, if heat loss is greater than production, temperature falls.

Classification of Fever Patterns

  1. Continuous Fever:

    • Minimal fluctuations (less than 3 degrees) throughout the day, remains above normal average.

  2. Intermittent Fever:

    • Alternates between elevated and normal temperatures.

  3. Remittent Fever:

    • Significant fluctuations (more than 3 degrees), never returning to normal.

Importance of Vital Signs in Healthcare

  • Vital signs (Temperature, Pulse, Respiration, Blood Pressure - TPR & BP) are critical indicators of health.

  • Accuracy in measurement is essential to detect changes in health status and inform treatment plans.

  • Non-verbal signs of discomfort or anxiety may impact measurement reliability and should be accounted for.

  • Patients may need time to stabilize after physical exertion or stress before accurate measurements can be taken.

Key Terms Related to Vital Signs and Temperature

  • Pyrexia: Condition of having a fever.

  • Hypotension: Low blood pressure, especially orthostatic (occurs upon standing).

  • Pulse Pressure: Difference between systolic and diastolic blood pressures; normal range: 30 to 50 mm Hg.

  • Orthopnea: Difficulty breathing when lying flat.

  • Cardiac Terms:

    • Myocardium: Middle layer of the heart.

    • Occlude: To close or stop up a passage.

  • Temperature Regulation: Managed by the hypothalamus, balancing heat production and loss.