VS

• Heat loss mechanisms

  • Radiation
  • Conduction
  • Convection
  • Vaporization
• 3Physiologic processes to increase body temperature

  1. Shivering increases heat production

  2. Sweating is inhibited to decrease heat loss

  3. Vasoconstriction decreases heat loss
• Factors affecting body temperature

  • Age
  • Diurnal variations (circadian rhythms)
  • highest : 4:00 – 6:00 pm- lowest : 4:00 – 6: 00 am
  • Exercise
  • HORMONES 0.3 to – 0.6 degrees centigrade ( .5-1 oF )
  • STRESS
  • ENVIRONMENT
• Factors affecting body's heat production

  • BMR - rate of energy utilization in the body required to maintain life-sustaining activities such as breathing
  • NOTE : the younger the person the higher the BMR
  • Muscle activity - increases BMR
  • Thyroxine output - increases the rate of cellular metabolism
  • Epinephrine, norepinephrine, & sympathetic stimulation/stress response - these hormones immediately increase the rate of cellular metabolism
• Core temperature


  Refers to the temperature of the deep tissues of the body (abdominal/pelvic cavity)
• Body temperature

  • Reflects the balance between the heat produced and heat lost from the body
  • Measured in degrees (Celsius or centigrade)
• Vital Signs

  1. Includes body temperature, pulse, respirations, and blood pressure

  2. These signs should be checked to monitor the functions of the body
• Regulation of body temperature

  Hypothalamus is responsible for the regulation of body temperature
• Surface temperature

  Temperature of the skin, subcutaneous tissue, and fat
• 4 Types of Hyperthermia

  • Intermittent - temp is elevated but returns to normal in 24 hrs. Highest in late PM and lowest in early AM
  • Remittent – a wide range of temperature fluctuations above 2 oC occurs over the 24hour period, all of which are above normal
  • Relapsing - a short febrile periods then 2 to 3 days normal temp
  • Constant – fluctuates minimally but always remains above normal
• Physiologic Mechanisms of Hypothermia

  • Excessive heat loss
  • Inadequate heat production to counteract heat loss
  • Impaired hypothalamic thermoregulation
• Stress


  • Stimulation of the sympathetic nervous system can increase the production of epinephrine and norepinephrine, thereby increasing metabolic activity and heat production
• Diurnal Variations (Circadian Rhythms)

  • Body temperature changes throughout the day
  • Highest temperature: 4:00 – 6:00 pm
  • Lowest temperature: 4:00 – 6:00 am
• Interventions for Hypothermia

  Assessing body temperature

  1. Site: Oral, Rectal, Axillary, Tympanic Membrane, Temporal Artery
  2. Advantages: ACCESSIBLE AND CONVENIENT, RELIABLE MEASUREMENT, SAFE AND NONINVASIVE, READILY ACCESSIBLE; REFLECTS THE CORE TEMPERATURE VERY FAST, SAFE AND NONINVASIVE
• Hypothermia


  • A core body temperature below the lower limit of normal
• Alterations in Body Temperature

  • Pyrexia/Hyperthermia
  • Fever in lay terms
  • Temperature above the normal range
  • Normal body temperature range: 36.5 to 37.5 degrees centigrade or 96.8 to 98.6 degrees Fahrenheit
  • Febrile or afebrile?
• Hormones


  • Progesterone secretion during ovulation for women increases body temperature by about 0.3 to 0.6 degrees centigrade
• Clinical Manifestations of Hypothermia

  • Decreased body temperature
  • Severe shivering
  • Feelings of cold and chills
  • Pale, cool waxy skin
  • Frostbite
  • Hypotension
  • Decreased urinary output
  • Disorientation
  • Drowsiness progressing to coma
• Clinical Signs of Hyperthermia (Fever)

  • Chills
  • Shivering
  • Pallid Skin
  • Gooseflesh
  • Increased pulse rate due to increased cardiac rate
  • Headache
  • Flushing of skin warm to touch
  • Restlessness
• Exercise

  • Strenuous activities can increase body temperature to as high as 38.3 to 40 degrees centigrade