Temperature Regulation

What is Conduction and factors affecting it

Definition: heat exchange by two object in contact

Factors

• Difference between 2 temperatures surface (heat flows from hot to cold)

• Surface area (increase in surface area leads to increase inheatloss

• Thermal conductivity of material (metal)

What is Convection and factor that affect it

definition: heat exchange by contact with a fluid (liquid or gases) that is flowing

• Heat is carried away from the body by air/water currents

Factors

• Speed and temperature of air/water

What is Radiation

Definition: when heat is transferred from a warmer body to cooler surrounds (environment) without physical contact

what is Evaporation and its factors

Definition: cooling of the body due to the vaporisation of sweat

• Heat is transferred to the skin surface via blood where it is released as sweat

• evaporation of sweat on the skin creates a cooling effect.

Factors:

• dependent on activity levels and environmental conditions – most effective in dry conditions

100% humidity results in no heat loss via evaporation as sweat cannot evaporate off the skin if their surrounding air is saturated

Rate of sweating depends on;

• Gender

• Number of sweat glands

• Body surface area

• How fit you are (how fit your cardiorespiratory system)

Factors for heat loss and why

Enviroment

• Ambient temp if its above the body core temp, evaporation is the only method of heat loss

• Forced convection (wind)

• Temperature radiating surfaces (light clothes will not absorb as much heat as dark clothing

• Relative humidity - if 100% no heat loss via evaporation

Age

• children dont sweat as much as there sweatglands arent as developed

Physiological state,

• Rate of heat production: the more work the athlete is doing the more heat they will produce due to muscles generating more contractions resulting in higher core temperature

• Hydration state: determines rate of evaporation as a reduction in plasma volume leads to decrease in sweat rate