A temperature around 37°C is required for our body in order to feel comfortable and in addition to perform all the necessary functions in the best way. If this temperature drops or rises, the body immediately reacts doing what is needed to maintain its temperature. In cold environments for example, the body generates heat by movement (shivering). On the other hand in too hot environments, cooling of the surface of the skin is achieved by evaporation. In general, there is a constant effort to keep the temperature of the body at the acceptable levels, which involves the continuous cooperation of the body with its environment. This is what we call metabolic rates. This rate can change approximately for every 1,5K increase or decrease of the temperature. What is more important is that this metabolic rate is associated with the activity that a person is doing at a specific time (physical activity). When the physical activity increases the heat produced by the body increases as well. As a result the perception of hot and cold is affected as well. | If the ambient temperature drops, the body first allows the extremities to cool in order to protect the functions of the brain, heart and other vital organs. |
The body’s heat balance can be expressed as
M ± R ± Cv ± Cd - E = ΔS (W)
where M = metabolic rate
Cv = convection
R = net radiation
Cd = conduction
E = evaporation heat loss
ΔS = change in heat stored [2]
M ± R ± Cv ± Cd - E = ΔS (W)
where M = metabolic rate
Cv = convection
R = net radiation
Cd = conduction
E = evaporation heat loss
ΔS = change in heat stored [2]
References
[1] Hegger et al., 2008, Energy manual - Sustainable architecture. Berlin: DETAIL
[2] Andris Auliciems et al, 2007, PLEA Notes - Thermal Comfort, p.6
[1] Hegger et al., 2008, Energy manual - Sustainable architecture. Berlin: DETAIL
[2] Andris Auliciems et al, 2007, PLEA Notes - Thermal Comfort, p.6