1. THERMOREGULATION

2. THERMOREGULATION
The process of maintaining core body temperature within an optimal physiological range

3. Thermoregulation Process that balances heat production and heat loss
- Maintain relatively constant core temperature
Heat produced = heat lost
- Hyperthermia and hypothermia - pathophysiologic consequences to altered thermoregulation

4. Thermoregulation
Hypothermia Normothermia Hyperthermia Hyperpyrexia
Scope of Thermoregulation Ranges from Hypothermia, to Normothermia, to Hyperthermia (Source: Giddens, 2013, St. Louis, MI: Mosby)
Severe Moderate Mild
<30°C °-34°C °-36°C
(80°F) (80°-93.2°F) (93.2°-96.8°F)
>41.5°C
(106.7°F)
36.5°-37.2°C
(97.7°-98.96°F)
>37.2°C
(98.96°F)

5. Thermoregulation Factors Affecting Heat Production and Conservation
→ Metabolic activity - basal metabolic rate (BMR)
→ Muscle activity
→ Chemical thermogenesis – epinephrine release
→ Sympathetic stimulation – stress response and
peripheral vasoconstriction
→ Fever

6. Thermoregulation Factors Affecting Heat Loss → Radiation → Conduction
→ Convection
→ Vaporization
■ Insensible water loss
■ Insensible heat loss
→ Vasodilation
→ Reduced muscle activity
→ Increased respirations

7. ANTECEDENTS REGULATION OF BODY TEMPERATURE
What factors play a role in regulating body temperature? Why?
What has to happen in order for thermoregulation to occur?

8. Regulation of Body Temperature
● Conscious Responses
 Putting on clothing, turning on fan
● Thermoreceptors in Shell and Core
▪ Peripheral thermoreceptors
 Skin has more receptors for cold than warmth
 Skin chilled → shivering, sweating,
vasoconstriction
▪ Central thermoreceptors
 Located in the spinal cord, abdominal organs, and
hypothalamus

9. Regulation of Body Temperature
● Hypothalamic Integrator controls core
temp
 Activates responses to Lower or raise body
temperature based on information received
from the thermoreceptors
 sensors detect heat
 cold sensors stimulated

10. Regulation of Body Temperature Temperature Control
The hypothalamus controls body temperature and signals for mechanisms to increase heat production or facilitate heat loss.
HYPOTHALMUS
HYPOTHALAMUS
Decreased Temperature
● Blood vessels constrict
●Sweat glands less active
●Skeletal muscles contract, causing shivering
Increased Temperature
● Blood vessels dilate – causing a flushed appearance to skin
● Sweat glands become more active

11. Factors Affecting Body Temperature
Age
Diurnal variations
Exercise
Hormones
Stress
Environment
- Extremes affect thermoregulation
- Newborns homeothermic

12. PAIR SHARE Pick a Partner Discuss developmental considerations
affecting thermoregulation in the
following groups and provide a
rationale for your answer.
Infants
Young children
Older adults

13. Risk Factors for Alterations in Thermoregulation
● Populations at Risk
- Infants and young children
- Older adults
- People living in very cold or very hot climates
- Low socioeconomic status
- Homeless
● Individual Risk Factors
- Impaired cognition
- Underlying health conditions
- Genetics
- Recreational and occupational exposures

14. Alterations Pyrexia - Body temperature above usual range
- Hyperpyrexia
- Febrile
- Afebrile
Hypothermia
- Excessive heat loss
- Inadequate heat production to
counteract loss
- Impaired hypthalamic thermoregulation

15. Physical Assessment Measuring body temperature
Body temperature measured in degrees on two scales
- Celsius (centigrade)
- Farenheit
- Conversion formulas:
■ From °F to °C
(Farenheit temperature – 32) x 5/9
■ From °C to °F
(Celsius temperature x 9/5) + 32

16. Physical Assessment, continued
Sites for measurement
- Oral
- Rectal
- Axilla
- Tympanic membrane
- Forehead
Advantages and disadvantages of sites

17. Physical Assessment, continued
Types of thermometers
- Mercury in glass → no longer used
- Electronic thermometer → fast and sanitary
- Basal thermometer → used for fertility
- Hyperthermia thermometer → °
- Chemical disposable thermometers
- Infrared thermometers
Developmental considerations

18. Assessment Comprehensive History - Biographical information
- Health history
- Family history (malignant hyperthermia)
- Recent illnesses or injuries
- Environmental exposures

19. Assessment Physical and Physiological
- Alterations in body temperature
- Hyperthermia
- Hypothermia
Diagnostic Tests
- Complete blood count (CBC) with differential
- Imaging studies → for suspected head trauma

20. Interventions
Maintain thermoregulatory mechanisms by reducing risk factors:
- Environmental Control and Shelter
▪ Elderly and young infants need warmer environment
▪ Infants and children should wear hats
▪ Maintain optimal temperature in home
- Adequate Hydration
- Physical activity

21. PAIR SHARE
Pick a Partner 1. Take your partner’s temperature and record it. 2. Convert °F to °C and back. 3. One student march in place for 5 minutes, and the other student sits quietly. 4. Retake temperatures and compare results. - Who has the highest temperature? - Connect exercise, increase in temperature, and risk for elderly in both hot and cold environment