Current Research on Geography, Earth Science and Environment Vol. 8

Introduction: Climate information expresses the type of climate, its spatial and temporal distribution, while thermal load information expresses the thermal load category or its frequency. To the best of our knowledge, no studies have investigated the relationship between the cyclonic weather type and human thermal load, either for the temperate. lowland, continental climate or for other climate types.

Aims: The aim of this study is to quantify human thermal load caused by cyclonic weather situations in the temperate, lowland, continental climate by using the new clothing thermal resistance model.

Methodology: The study was conducted at Martonvásár (Hungary, Central Europe), in the period 2021-2025. The study investigated thermal and evaporative heat exchange between humans and the atmosphere using a longitudinal observational dataset. A single observer recorded 10-minute atmospheric conditions across warm front, cold front, and clear-sky cyclonic situations. Meteorological variables (air temperature, humidity, wind, radiation, cloud cover, and pressure) were combined with fixed human anthropometric and metabolic parameters. A “comfortable clothing” resistance model was applied to estimate clothing thermal resistance and compensatory latent heat flux under varying environmental conditions.

Results: The most important results are as follows: 1) In warm front weather situations, there can not only be an environmental heat deficit, but also a surplus. 2) In heat deficit situations, the clothing’s thermal resistance (r_cl,t) values ​​varied between 0 and 2 clo. 3) Heat excess conditions are quantified by the compensatory latent heat flux density variable λE^comp. λE^comp values ​​registered during warm front passages varied between 0 and 140 Wm^-2. At such times, there was precipitation; these are "warm rains". 4) In cold front weather situations, r_cl,t values ​​varied between 2 - 2.6 clo for the largest registered heat deficits. 5) During cold front passages, the heat excess can be greater than during warm front passages. λE^comp values ​​varied between 0 - 240 Wm^-2, but in one case  a value of 560 Wm^-2 was registered. 6) Finally, it was demonstrated that under heat-deficient conditions, the difference in thermal load between an individual and a normative person increases as the differences in their anthropometric characteristics become greater.

Conclusion: The study concluded that the new clothing index model used can be successfully applied to estimate human thermal load in weather situations causing both heat deficiency and heat excess. Cold front movements cause larger fluctuations in human thermal load compared to warm front movements. Cloud cover plays a crucial role in determining the magnitude of these fluctuations.