Module 2- Mechanisms of Heat Loss

Question 1

What are the four mechanisms of heat loss?

Answer 1

1. Conduction
2. Convection
3. Evaporation
4. Radiation

Question 2

How is heat lost through conduction?

Answer 2

Conductive loss of heat occurs when a person comes in direct contact with either a solid or a liquid.

Question 3

What mechanism of heat loss occurs during wind chill? Explain.

Answer 3

Convection. Heat is lost through convection when liquid or air moves across the skin. Heat loss will increase when this occurs.

Question 4

What is evaporation?

Answer 4

Evaporation is the loss of heat due to liquid on the skin, or from clothing in contact with the skin, changing its state from a liquid to a gas. For example when a person sweats, falls in the water or when it rains.

Question 5

How do you reduce evaporative heat loss?

Answer 5

The best way to reduce evaporative heat loss is to keep clothing as dry as possible and/or use a protective vapour barrier on a subject that is wet/has wet clothing to slow evaporative heat loss.

Question 6

What is radiation?

Answer 6

Radiation happens through transmission of electromagnetic energy through space from one object to another.

Question 7

What does a reflective blanket do?

Answer 7

A reflective blanket can reflect heat back to the source but this effect will be minimal with a cold patient. The main function of these blankets is to act as an effective vapour barrier.