The investigation concerned the physical thermoregulatory mechanism in hens
kept in the conditions of low air temperature (x = 9.8 degreesC), high hum
idity (84.8%) and excessive body heat loss (39.3 mW/cm(2)). The measurement
s were taken: internal body temperature, temperature of feathered (thermost
able points) and bare skin areas (thermolabile points), and the Burton circ
ulatory index was determined. It was discovered that air movement and body
heat loss had the most significant influence on the temperature of thermost
able points and - indirectly through tissue conductivity - on internal body
temperature. The value of the thermo:' stable points on the skin was affec
ted by all the examined weather factors. The fact that the Burton index at
bare skin areas was four times lower than in thermostabile points proves th
e good skin insulation of these skin points.