Superficial Heat and Cold Flashcards
What is the bodies normal core temperature?
37 Degrees C +/- 1 Degree
Hypothermia=Rectal temp <35 Deg C
Hyperthermia= Rectal temp >38 Deg C
What degree is skin an other peripheral tissues?
Slightly less than core temperatures at 32-34 deg C
How do you convert C to F?
C=(f-32)x 5/9
F= Cx9/5 +32
What is Heat Exchange between skin and air?
Via Evaporation: from skin and respiratory passages
Via Non- Evaporation: Radiation, conduction, and convection
What is Heat Exchange in the Body?
Countercurrent exchanged: Cool venous blood from extremities warmed by arterial blood flow from core
What is radiation?
Energy being transmitted from one surface to another- typically to heat up that surface; ex: sunlight or infrared lighting
What is Conduction?
two surfaces together that have different temperatures Ex: Hot pack on someone or cold pack
What is Convection?
Two surfaces together that are different temperatures and one surface continually moves across the other
Ex: Air blown by fan; water being moved by tissues via whirlpool
What do physiological effects on local heating depends on?
Degree of tissue temperature rises (TTR)
Gradient- greater temp gradient gives greater TTR
Specific heat- higher specific heat= more energy to heat, slower loss
Volume- of tissue exposed
Rate- heat is applied
* If slow transfer, TTR is balanced by blood carrying heat away
* If transfer faster than blood can carry heat away and TTR is too great, pain and burns result
What are the physiological effects of heat?
- Vasodilation (brings in more nutrients, picks up more waste)
- Increase metabolism ( for every 10 Deg C rise in temp, there is a 2-3 fold increase in the rate of metabolism
- Pain Relief
- Decreases Stiffness
What are some additional physiological effects of Heat?
- enhances extensibility of tissue
* reduces muscle spasms/ Decreased strenght
What are some general precautions for Heat?
- Areas of decreased sensation and innervation
- Areas of decreased circulation
- treating large volumes of tissues
- Poor thermal regulation-children and elderly
- During pregnancy
- cardiac insufficeincy
- metal in the area
- Areas of watery edema- increased risk of burn
- scars and new skin
- over areas where topical counterirritants have been recently applied
Contraindications for Heat?
- areas of arterial insufficiency or arterial disease
- Areas prone to hemorrhage
- Acute inflammatory site
- Elevating tissue temperature in area of malignancy
- Thromnophlebitis
- Impaired cognitive function
What are hot packs?
Heat transferred by conduction (superficial); considered moist heat
How many layers of towels should you use with hot packs?
6-10 Layers; always check 5-6 minutes as the heat is reaching max temperature around that time; patient should feel warmth similar to towels fresh out of the dryer