Heat storage, not sensible heat loss, increases in high temperature, high humidity conditions

Because evaporative cooling is the principal avenue of heat loss at high am bient temperatures, high humidity superimposed on high temperature presents poultry with an additional thermal challenge. Whenever body temperature ex ceeds ambient temperature, sensible heat loss (radiation, conduction, and c onvection) to the environment will occur. The generally accepted model of h eat balance, which states that when ambient temperature increases homeother ms will endeavour to maximize sensible heat loss before resorting to evapor ative heat loss, was recently challenged. However, several factors that can influence heat balance were not considered in the reasoning pursued in tha t challenge. In this paper the theory behind heat balance models is discuss ed and the data that were used to challenge the model are reanalysed. The q uestion of whether poultry are capable of physiologically increasing sensib le heat loss under hot, humid conditions remains unanswered and presents an area worthy of future study.