Related Experiment Video
Updated: Jan 27, 2026

Prevention of Heat Stress Adverse Effects in Rats by Bacillus subtilis Strain
Published on: July 11, 2016
A free software to predict heat strain according to the ISO 7933:2018
Leonidas G Ioannou1, Lydia Tsoutsoubi1, Konstantinos Mantzios1
1FAME Laboratory, School of Exercise Science, University of Thessaly, Greece.
Abstract:
Our primary objective in this study was to design and implement the FAME Lab PHS Calculator software (PHSFL) (www.famelab.gr/research/downloads), a free tool to calculate the predicted heat strain of an individual based on ISO 7933:2018. Our secondary objective was to optimize the practicality of the PHSFL by incorporating knowledge from other ISO standards and published literature. The third objective of this study was to assess: (i) the criterion-related validity of the PHSFL by comparing its results against those obtained using the original ISO 7933:2018 code; and (ii) the construct validity of the PHSFL by comparing its results against those obtained via field experiments performed in human participants during work in the heat. Our analysis for criterion validity demonstrates that PHSFL provides valid results within the required computational accuracy, according to Annex F of ISO 7933:2018. The construct validity showed that root mean square errors (RMSE) and 95% limits of agreement (LOA) were minimal between measured and predicted core temperature (RMSE: 0.3°C; LOA: 0.06 ± 0.58°C) and small between measured and predicted mean skin temperature (RMSE: 1.1°C; LOA: 0.59 ± 1.83°C). In conclusion, the PHSFL software demonstrated strong criterion-related and construct-related validity.
More Related Videos
Related Concept Videos
Predicting Molecular Geometry
Quantifying Heat
Specific Heat
For example, increasing the temperature of one gram of water by 1°C requires one calorie of heat energy and can be written as 1 cal/g-°C, or...
Heat Flow and Specific Heat
Heating and Cooling Curves
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...
Prediction Intervals
However, the point estimate is most likely not the exact value of the population parameter, but close to it. After calculating point estimates, we construct interval estimates, called confidence intervals or prediction intervals. This prediction interval comprises a range of values unlike the point estimate and is a better predictor of the observed sample value, y.

