Question

Write 7-10 sentences describing how the three different types of heat transfer apply to the human body (both externally and internally).  Be sure to describe how this is helpful (or harmful) to our survival. Think about how this changes if we are in an extremely hot or cold environment (both externally and internally).

Answer 1

The hypothalamus in brain act as a thermostat which controls the temperature of the body. when temperature of the surroundings is high then blood circulation becomes high and heat dissipates through the skin and there is sweating which evaporates and makes skin cool. Similarly when temperature of outside is low hypothalamus shivers our body and generate heat. This is internal mechanism.

Now body losses or gains heat externally through 4 process.

1. Conduction- It is direct transfer of heat through skin in the air, when body is in hot area or cold area.

2. Convection- In this method heat transfer to the air surroundings the body. This also happen in water also. When the temperature of the body high then its start heating water near the water of the skin and losses heat and then hot water moves away and replaced by new cold water. When body losses more heat than body can replace heat then hyperthermia happens.

3.Radiation- When heat transfer via infrared waves then we call radiation. On a sunny day heat from sun transfer to body via radiation. Similerly heat transfer to air via radiation when body is hot than air.

4. Evaporation- When surroundings is hot, body generate sweat which evaporate and makes body cool. So heat transfers via water through evaporation.