Human Body Specific Heat

Overview

Engineering reference data for Human Body Specific Heat in thermodynamics.

Key Formulas

First Law

$\Delta U = Q - W$

Energy is conserved — heat added minus work done.

Ideal Gas Law

$PV = nRT$

Relates pressure, volume, and temperature of an ideal gas.

Heat Transfer

$Q = mc\Delta T$

Sensible heat transfer.

Carnot Efficiency

$\eta = 1 - T_C/T_H$

Maximum efficiency between two temperatures.

Variables

Symbol	Description	Unit
$U$	Internal energy	J
$Q$	Heat	J
$W$	Work	J
$P$	Pressure	Pa
$V$	Volume	m³
$T$	Temperature	K

Properties

The specific heat of the human body is highly dependent on its composition. The widely used average value of 3470 J/(kg·°C) is based on common assumptions, while the alternative average of 2980 J/(kg·°C) is a calculated value that reflects a range of 2444 to 3390 J/(kg·°C). This variation exists because different tissue types (muscle, fat, bone) have different specific heats. Up to 60% of the adult human body is water, which has a high specific heat of 4187 J/kg·°C and is the primary reason for the body's high overall heat capacity.

Unit Conversions

$1 \ \frac{\text{J}}{\text{kg·°C}} = 2.389 \times 10^{-4} \ \frac{\text{kcal}}{\text{kg·°C}} = 2.389 \times 10^{-4} \ \frac{\text{Btu}}{\text{lb}_m \cdot °F}$

References

• Original Source