TEMPERATURE REGULATION | PALICPIC 05/02/25

1. SENSORS IN THE PERIPHERY AND IN THE CORE

2. AN INTEGRATOR IN THE HYPOTHALAMUS

3. EFFECTOR SYSTEM

3 THREE MAIN PARTS OF THE SYSTEM THAT REGULATES BODY TEMPERATURE:

SENSORS IN THE PERIPHERY AND IN THE CORE

Most sensors are in the skin and it can detect cold more than warmth.

AN INTEGRATOR IN THE HYPOTHALAMUS

- The center that controls core temperature.

- If it detects heat, it sends signals to reduce temperature to decrease heat production and increase heat loss. If it detects cold, it sends signals to increase heat production and decrease heat loss.

EFFECTOR SYSTEM

- Adjusts the production and loss of heat.

Cold-sensitive receptors for heat production

(vasoconstriction, shivering and release of epinephrine to increase cellular metabolism).

Warm-sensitive receptors for heat loss

(sweating and peripheral vasodilation).

putting on additional clothes

BEHAVIOR CONTROL Cold

turning on a fan or air conditioning.

BEHAVIOR CONTROL Hot

1. BASAL METABOLIC RATE (BMR)

2. MUSCLE ACTIVITY

3. THYROXINE OUTPUT

4. EPINEPHRINE AND NOREPINEPHRINE AND SYMPATHETIC STIMULATION / STRESS RESPONSE

5. FEVER

[5] FACTORS AFFECTING HEAT PRODUCTION:

BASAL METABOLIC RATE (BMR)

Rate of energy utilization in the body required to maintain essential activities (breathing). Metabolic rate decreases with age. The younger the person, the higher the BMR.

MUSCLE ACTIVITY

Including shivering increases the metabolic rate.

Shivering

is a compensatory mechanism of an increase in temperature that will manifest into a high fever spike.

thyroxine output

Increased ______________ increases the rate of cellular metabolism throughout the body

EPINEPHRINE AND NOREPINEPHRINE AND SYMPATHETIC STIMULATION / STRESS RESPONSE

These hormones immediately increase the rate of cellular metabolism in many body tissues.

FEVER

Increases the cellular metabolic rate and thus increases the body's temperature further

BODY TEMPERATURE

Reflects the balance between the heat produced and the heat lost from the body:

degrees

measured in heat units called

1. CORE TEMPERATURE

2. SURFACE TEMPERATURE

[2] TYPES OF TEMPERATURE

HEAT BALANCE

The amount of heat produced by the body equals the amount of heat lost.

1. RADIATION

2. CONDUCTION

3. CONVECTION

4. . EVAPORATION

[4] HEAT LOSS MECHANISMS

RADIATION

The transfer of heat from the surface of one object to the surface of another without contact between the two objects.

Example: Infrared rays.

CONDUCTION

The transfer of heat from one molecule to a molecule of lower temperature and this can not take place without contact between the molecules and normally accounts for minimal heat loss.

CONVECTION

Dispersion of heat by air currents

EVAPORATION

The continuous vaporization of moisture from the respiratory tract and from the mucosa of the mouth and from the skin.

INSENSIBLE WATER LOSS

The continuous and unnoticed water loss.

INSENSIBLE HEAT LOSS

- The unnoticed water loss plus heat loss and accounts for about 10% of basal heat loss.

- As body temperature incre

1. AGE

2. DIURNAL VARIATIONS

3. EXERCISE

4. HORMONES

5. STRESS

6. ENVIRONMENT

[6] FACTORS AFFECTING BODY TEMPERATURE

Infants

greatly influenced and must be protected from extreme temperatures.

Children

vary until puberty.

Older adult

sensitive to extreme environmental temperature due to decreased thermoregulatory controls.

Older people (75 y/o and more)

at risk for hypothermia due to loss of subcutaneous fat, inadequate diet, lack of activity, reduced thermoregulatory efficiency.

DIURNAL VARIATIONS

Body temperatures normally change throughout the day, varying as much as 1.0°C (1.8°F) between the early morning and the late afternoon.

4PM and 6PM

Body temmperature Highest: between ____ and ____.

sleep, 4AM and 6AM

body temperature Lowest: during _______, between ____ and ____.

38.3°C to 40°C

Hard work or strenuous exercise can increase body temperature to as high as ____ to ______ measured rectally

0.3°C to 0.6°C

in women, progesterone secretion at the time of ovulation raises body temperature by about _____ to ____ above basal temperature.

STRESS

Stimulation of the sympathetic nervous system can increase metabolic activity and heat production.

ENVIRONMENT

can affect a client's temperature regulatory systems. If the body temperature is assessed in a very warm room and cannot be modified by convection, conduction, or radiation, the temperature will be elevated.

36 - 37.5 degrees Celsius

96.8 to 99.5 degrees fahrenheit

Normal body temperature: __ to __ degrees Celsius (___to __ degrees Fahrenheit).

PYREXIA

- Body temperature

above the usual range.

- Known as hyperthermia or fever in Layman's term.

Febrile

patient with fever

Afebrile

patient without fever

1. INTERMITTENT FEVER

2. REMITTENT FEVER

3. RELAPSING FEVER

4. CONSTANT FEVER

[4] TYPES of fever

INTERMITTENT FEVER

Body temperature alternates at regular intervals.

➢ Example: Malaria

REMITTENT FEVER

Wide range of temperature fluctuations (mostly above normal) in a 24 hour period.

➢ Example: Common colds or influenza

RELAPSING FEVER

Short febrile periods of a few days with periods of 1-2 days of normal temperature.

➢ Example: Infection

CONSTANT FEVER

Body temperature fluctuates minimally but still above normal

➢ Example: Typhoid fever

FEVER SPIKE

Temperature that rises to fever level rapidly following a normal temperature and then returns to normal within a few hours.

➢ Example: Bacterial blood infection

HEAT EXHAUSTION

Results of excessive heat and dehydration.

Signs: paleness, dizziness, nausea, vomiting, fainting, and moderately increased temperature.

HEAT STROKE

- Generally exercising in hot weather, have warm,flushed skin and often do not sweat.

- A temperature of 41.1 degrees Celsius (106 degrees fahrenheit).

- Signs: Unconscious, delirious, seizures.

1. onset (cold/chill phase)

2. course (plateau phase)

3. defervescnence (fever abatement / flush phase)

clinical manifestations:

onset (cold/chill phase)

- new set point of body temperature

sign:

- increase HR and RR

- shivering

- pallid, cold skin

- cyanotic nail bed

- gooseflesh

appearance of the skin

COURSE (PLATEAU PHASE)

- A new set point of core temperature.

- The person feels neither cold or hot and no longer experiences chills.

Signs: absence of chills, skin that feels warm, photosensitivity, glassy-eyed appearance, increased pulse and respiratory rate, increased thirst, mild to severe dehydration, drowsiness, restlessness, delirium, or convulsion, herpetic lesions of the mouth, loss of appetite, and malaise, weakness, and aching muscles.

DEFERVESCENCE

- When the cause of high temperature is suddenly removed so the hypothalamus now attempts to lower the body temperature.

Signs: skin that appears flushed and feels warm, sweating, decreased shivering, and possible dehydration.

vital signs

During the course of fever, the nurse needs to monitor the client's ____________ closely.

decreasing heat loss

During the chill phase, help the client in ______________.

heat loss, heat production

During the flush phase, take measures to increase _______ and decrease ___________.

color and temperature

Assess skin ______and _______.

WBC

Monitor ____ count, hematocrit value and other pertinent laboratory reports for indicators of infection and dehydration.

2.5-3

Provide adequate nutrition and fluids (_____ L/day) to meet the increased metabolic demands and prevent dehydration.

oral hygiene

Provide ______ to keep the mucus membranes moist.

TSB (Tepid Sponge Bath)

Provide _____________________ to increase heat loss through conduction

HYPOTHERMIA

Core body temperature below the lower limit of normal.

1. EXCESSIVE HEAT LOSS

2. INADEQUATE HEAT PRODUCTION TO COUNTERACT HEAT LOSS

3. IMPAIRED HYPOTHALAMIC REGULATION

[3] PHYSIOLOGICAL MECHANISMS OF HYPOTHERMIA

1. INDUCED

2. ACCIDENTAL

[2] TYPES OF hypotherermia

INDUCED

deliberate lowering of the body temperature to decrease the need of oxygen by the body tissues like in surgeries

ACCIDENTAL

can occur as a result of exposure to a cold environment, immersion in cold water, lack of adequate clothing, shelter, or heat

1. hypothermia

2. mild hypothermia

3. severe hyperthermia

stages of hypothermia:

hypothermia

In __________, remove the client from the cold and try rewarming the client's body

mild hypothermia

In _____________, the body is rewarmed by applying blankets

severe hyperthermia

With ___________, a blanket and warm IVF is given.

1. ORAL

2. RECTAL

3. AXILLARY

4. TYMPANIC MEMBRANE

5. TEMPORAL ARTERY

ASSESSING BODY TEMPERATURE Most common sites:

30

ORAL - Wait for ___ mins if the client had cold or warm food and drinks or just had smoked.

RECTAL

Very accurate but contraindicated for those undergoing rectal surgery, diarrhea, disease of the rectum, immunosuppressed, clotting disorder and hemorrhoids.

AXILLARY

It is preferred in newborns because it is accessible and safe; lower than rectal.

- if readings are elevated, the nurse must recheck in other sites.

TYMPANIC MEMBRANE

- A frequent site for estimating core body temperature. I

- t tends to be imprecise if the probe fits too loosely in the ear canal.

TEMPORAL ARTERY

this is measured on the forehead; most useful but shows inconsistent readability.

1. Mercury-in-glass thermometers

2. Electronic thermometer: (a) Basal & (b) Hypothermia

3. Chemical disposable thermometers 4. Temperature sensitive tape

5. Infrared thermometers

6. Temporal artery thermometers

[6] TYPES OF THERMOMETERS

Mercury-in-glass thermometer

traditional one and most common used thermometer however, it is hazardous due to exposure to mercury

Electronic Thermometers

an provide a reading in only 2 to 60 seconds, depending on the model. The equipment consists of an electronic base, a probe, and a probe cover. Models have different circuit and probe for oral and rectal measurement.

1. Basal

2. Hypothermia

2 types of Electronic Thermometers

Basal Thermometer

is caliberated with 0.1°F intervals and is for fertility purposes, indicating the temperature rise that is associated with ovulation

hypothermia thermometer

have a greater low range than everyday thermometers, usually measuring temperatures from 27.2 °C to 42.2 °C (81 °F to 108 °F).

Chemical Disposable Thermometer

also used to measure body temperature. Chemical thermometers have a liquid crystal dots or bars that change color to indicate temperature.

Temperature-sensitive tape

-It does not indicate the core temperature.

Infrared thermometer

- sense the body heat in the form of infrared energy given off by a heat source.

Temporal artery thermometer

determine temperature using a scanning infrared thermometer that compares the artery of the forehead to the temperature in the room and calculates the heat balance to approximate the core temperature of the blood in the pulmonary artery.

C = (Fahrenheit temperature - 32) x 5/9

To convert from Fahrenheit to Celsius

F = (Celsius temperature x 9/5) + 32

To convert from Celsius to Fahrenheit