Conclusion
Re-evaluation of the temperature humidity index provides the industry with solutions for tomorrow. Through this study it proved to be underestimated for current high producing dairy cows. Results show that THI beginning at 68 affect dairy cows adversely during heat stress. Therefore, cooling methods on commercial dairy farms should be implemented earlier to prevent these effects. Parameters indicative of heat stress were also shown to be correlated with THI and therefore are measurements that can be obtained to evaluate the degree of heat stress in the animal. Further research should be conducted to evaluate the relationship between BGHI and physiological parameters as with the addition of solar radiation effects perhaps the correlations would be greater; especially after arithmetic means demonstrate strong correlations between BGHI or THI to skin surface temperature and respiration rate.