The Human Thermal Load of Mornings with Clear Skies in the Hungarian Lowland
Round 1
Reviewer 1 Report (Previous Reviewer 1)
Comments and Suggestions for AuthorsWhile the manuscript provides a novel and detailed investigation of the human thermal climate on clear-sky mornings in the Hungarian lowland, several significant issues must be addressed before the paper can be considered for publication.
Clarity and Structure:
The manuscript contains sections that are overly dense and difficult to follow. The authors should improve the clarity of explanations, especially in the methods and results sections, by simplifying language and ensuring consistent terminology. Additionally, the structure can be enhanced by clearly separating model description, parameterization, and results discussion.
Justification of the Model:
While the rcl–To model is presented as a novel approach, a more detailed justification and comparison with established thermal comfort indices (e.g., PET, UTCI) are needed. Specifically, explain the added value of using rcl–To over more widely used models.
Validation and Uncertainty:
The model output should be validated against either subjective thermal perception data or independent datasets. Currently, the model's reliability is assumed rather than demonstrated. Including uncertainty analysis or sensitivity testing would strengthen the study's credibility.
Figures and Tables:
Several figures (e.g., Figures 3–5) lack adequate captions or explanations in the text. The graphical presentation should be more self-contained and clarified to ensure that readers can interpret the results without excessive cross-referencing.
Generalization of Findings:
The manuscript focuses on a highly specific climatic and temporal window (clear-sky mornings in one location). The authors should discuss the extent to which the findings can be generalized to other regions or weather types, or clarify that the results are local and context-specific.
Author Response
REPLY TO REVIEWERS' COMMENTS
RESPONSES ARE IN RED
REVIEWER-1
Comments and Suggestions for Authors
While the manuscript provides a novel and detailed investigation of the human thermal climate on clear-sky mornings in the Hungarian lowland, several significant issues must be addressed before the paper can be considered for publication.
Clarity and Structure:
The manuscript contains sections that are overly dense and difficult to follow. The authors should improve the clarity of explanations, especially in the methods and results sections, by simplifying language and ensuring consistent terminology.
ANSWER: We did not make any changes to the structure of the thesis. Section 2 contains 5 subsections; the introduction of the region is in a separate section; section data was divided as needed: into human data and weather data subsections; the other sections are structurally simple and do not require division. In our opinion, our language is simple and the terminology used is consistent.
Additionally, the structure can be enhanced by clearly separating model description, parameterization, and results discussion.
ANSWER: Model description is in section 2.2, parameterization is in section 2.3, discussion is in section 6. We don't know what the reviewer meant, we don't understand the comment, since the listed elements are in separate chapters.
Justification of the Model:
While the rcl–To model is presented as a novel approach, a more detailed justification and comparison with established thermal comfort indices (e.g., PET, UTCI) are needed.
ANSWER: We have done this in our previous works (In this work, citations [22] and [32]). We have not done it here so as not to repeat ourselves.
Specifically, explain the added value of using rcl–To over more widely used models.
ANSWER: The advantages were also described in the article: it parameterizes M, but at the same time the model is simple. We haven't written about the disadvantages. Disadvantages: it can only be used in weather situations with excess heat by parameterizing or measuring sweating. You can read more about this in the article with following link: https://doi.org/10.1002/met.70041
Validation and Uncertainty:
The model output should be validated against either subjective thermal perception data or independent datasets. Currently, the model's reliability is assumed rather than demonstrated.
ANSWER: The validation of model is done in the following works: in this work citations [10,11] and also a work with the following link: https://doi.org/10.1007/s00704-025-05433-y comparing it with generic climate classification methods; in this work citations [22], [32] comparing it with UTCI and PET indices.
Including uncertainty analysis or sensitivity testing would strengthen the study's credibility.
ANSWER: sections 5.3 and 5.4 are about sensitivity tests. Further sensitivity tests analaysis can be found in [29], [31] or on the suggested link: https://doi.org/10.1007/s00704-025-05433-y.
Figures and Tables:
Several figures (e.g., Figures 3–5) lack adequate captions or explanations in the text. The graphical presentation should be more self-contained and clarified to ensure that readers can interpret the results without excessive cross-referencing.
ANSWER: We found no errors in the figures and their titles, and in our opinion they are understandable.
Generalization of Findings:
The manuscript focuses on a highly specific climatic and temporal window (clear-sky mornings in one location). The authors should discuss the extent to which the findings can be generalized to other regions or weather types, or clarify that the results are local and context-specific.
ANSWER: In our opinion, the human thermal load results obtained in the Hungarian lowland with a Cfb climate can be extended to all areas with a Cfb climate, regardless of their geographical location. Based on the insights of Humboldt and Köppen, we can say that areas with the "same" climate also have the "same" vegetation, regardless of their geographical location. At the scale of biomes, vegetation is a climate indicator. Since vegetation is strongly dependent on heat supply, the vegetation of areas with different geographical locations but the "same" heat supply can be considered "the same". Since the environmental (climatic) heat load of humans and vegetation is the same, the human heat load is the same in areas with different geographical locations but the same climate. This is valid – of course – on biome, global scale. This makes sense to us, so we didn't include this overly long explanation, which doesn't fit thematically into the thesis.
Submission Date
20 March 2025
Date of this review
14 Apr 2025 04:41:30
Author Response File: 
Author Response.pdf
Reviewer 2 Report (Previous Reviewer 2)
Comments and Suggestions for AuthorsThe paper selected three people from the database for detailed analysis, but the sample is too small. It is suggested to explain why only three people are selected? Can the analysis requirements be met? Are the results statistically significant? and so on to explain.
Author Response
REPLY TO REVIEWERS' COMMENTS
RESPONSES ARE IN RED
REVIEWER-2
Comments and Suggestions for Authors
The paper selected three people from the database for detailed analysis, but the sample is too small.
ANSWER: It's not the number of people that matters, but the extent of the differences between people. The differences in BMI and M between these 3 people almost cover the adult database.
It is suggested to explain why only three people are selected? Can the analysis requirements be met? Are the results statistically significant? and so on to explain.
ANSWER: The impact of human variability on human thermal load was examined in a separate study, cited in the article [41].
Submission Date
20 March 2025
Date of this review
29 Mar 2025 04:32:33
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
Comments and Suggestions for AuthorsDear Authors;
I suggest the following revisions to improve the manuscript:
The phrase “human thermal climate” could be ambiguous to readers. Consider clarifying it with more direct language such as “thermal comfort”.
Generally, The abstract does not sufficiently contextualize why clear-sky mornings are of particular interest—why is this specific time of day relevant from a physiological or climatological perspective?
The methodological novelty is briefly stated but should be clarified more explicitly in the abstract.
The rationale for choosing clear-sky mornings is mentioned, but the reader is not clearly informed about why thermal load during these periods is understudied or significant for health, energy use, or behavioral adaptation.
The use of multiple Hungarian-focused studies narrows the scope; consider including comparative international works to emphasize the broader relevance of the study.
The explanation of equations (2) and (3) is highly technical. There is little effort to interpret the variables for a broader scientific audience. It would be helpful to explain the significance of parameters in more intuitive terms.
Only three individuals were selected for simulation. This is a very small sample for assessing interpersonal variability, especially considering the availability of a large database. Why were only males selected? Was this intentional or an oversight?
The paper repeatedly attributes high heat deficits to clear skies, but wind speed, radiation, and humidity are also acknowledged as variable. It would be appropriate to include multivariate analysis or at least correlation matrices to distinguish the influence of each factor.
The authors claim this is the first study of its kind in Cfb climates during morning hours, but there is limited effort to position this against similar works globally. The claim may appear overstated without a broader literature comparison.
Consider discussing how the model could be generalized to other locations or populations, not only in Hungary.
The conclusion repeats the results but lacks reflective insight. What are the broader implications for public health, urban design, or forecasting?
How could this model be integrated into decision-making tools or weather services?
I hope the authors find these comments constructive for improving the manuscript.
Author Response
REPLY TO REVIEWERS' COMMENTS
RESPONSES ARE IN RED
REVIEWER-3
Comments and Suggestions for Authors
Dear Authors;
I suggest the following revisions to improve the manuscript:
The phrase “human thermal climate” could be ambiguous to readers. Consider clarifying it with more direct language such as “thermal comfort”.
ANSWER: The term "human thermal climate" has been rewritten as "human thermal load".
Generally, The abstract does not sufficiently contextualize why clear-sky mornings are of particular interest—why is this specific time of day relevant from a physiological or climatological perspective?
ANSWER: We have modified the summary, the modified version includes the justification. The amendment is as follows: The climate of the Hungarian lowland (Central European region, Pannonian Plain area) can be characterized by Köppen's Cfb climate formula (C – warm temperate, f – no seasonality in the annual course of precipitation, b – warm summer). This characterization does not provide information about human thermal load and thermal perception. The aim of this work is to fill this gap. We focused on the morning, clear-sky periods of the day, when the heat supply provided by the weather is the lowest. Human thermal load of clear-sky mornings was estimated by using the new clothing thermal resistance–operative temperature (rcl–To) model. In contrast to IREQ-type (Required Clothing Insulation) models, the model parametrizes the total metabolic heat flux density (M) as a function of anthropometric data (body mass, height, sex, age).
The methodological novelty is briefly stated but should be clarified more explicitly in the abstract.
ANSWER: It is done by the sentence: In contrast to IREQ-type (Required Clothing Insulation) models, the model parametrizes the total metabolic heat flux density (M) as a function of anthropometric data (body mass, height, sex, age).
The rationale for choosing clear-sky mornings is mentioned, but the reader is not clearly informed about why thermal load during these periods is understudied or significant for health, energy use, or behavioral adaptation.
ANSWER: The reason was also written in the summary: „We focused on the morning, clear-sky periods of the day, when the heat supply provided by the weather is the lowest.” We did not write about the practical applicability of the information, despite the fact that it is practical, we thought that this was not the direct topic of the thesis.
The use of multiple Hungarian-focused studies narrows the scope; consider including comparative international works to emphasize the broader relevance of the study.
ANSWER: To the best of our knowledge, there is no study in the literature with a similar topic and methodology.
The explanation of equations (2) and (3) is highly technical. There is little effort to interpret the variables for a broader scientific audience. It would be helpful to explain the significance of parameters in more intuitive terms.
ANSWER: We consider the methodological description to be appropriate, as it has proven to be appropriate in previous works (in this work, citations [10], [22], [29], [31], [41]).
Only three individuals were selected for simulation. This is a very small sample for assessing interpersonal variability, especially considering the availability of a large database.
ANSWER: It's not the number of people that matters, but the extent of the differences between people. The differences in BMI and M between these 3 people almost cover the adult database. The impact of human variability on human thermal load was examined in a separate study, cited in the article [41].
Why were only males selected? Was this intentional or an oversight?
ANSWER: The answer is in the work. It is as follows: „Sex was not a consideration when selecting individuals. Our only consideration was that the M and BMI values should be as different as possible. We aimed to ensure that the M and BMI values cover the adult value range of the database as much as possible.”
The paper repeatedly attributes high heat deficits to clear skies, but wind speed, radiation, and humidity are also acknowledged as variable. It would be appropriate to include multivariate analysis or at least correlation matrices to distinguish the influence of each factor.
ANSWER: The most important variable in regulating morning heat deficits is the downward atmospheric radiation. This depends on cloudiness, air tempetature and humidity. Cloudiness is non-existent, air temperature is changeable, air humidity is higher, all of this provides much less downward atmospheric radiation compared to a cloudy sky. Wind speed is generally small and can be considered independent of downward atmospheric radiation. Of the meteorological elements listed, cloudiness is the most important. We have covered this in detail in our following study: Ács F, Kristóf E, Zsákai A, 2025: Human thermal load of foggy and cloudless mornings in the cold season. Geofizika, 42, in press, DOI: 10.15233/gfz.2025.42.1.
The authors claim this is the first study of its kind in Cfb climates during morning hours, but there is limited effort to position this against similar works globally. The claim may appear overstated without a broader literature comparison.
ANSWER: We intensively searched for studies with similar topics and methodologies, but we found none. This may also be due to the fact that generic climate classification methods are not linked to methods for estimating human thermal load.
Consider discussing how the model could be generalized to other locations or populations, not only in Hungary.
ANSWER: In our opinion, the human thermal load results obtained in the Hungarian lowland with a Cfb climate can be extended to all areas with a Cfb climate, regardless of their geographical location. Based on the insights of Humboldt and Köppen, we can say that areas with the "same" climate also have the "same" vegetation, regardless of their geographical location. At the scale of biomes, vegetation is a climate indicator. Since vegetation is strongly dependent on heat supply, the vegetation of areas with different geographical locations but the "same" heat supply can be considered "the same". Since the environmental (climatic) heat load of humans and vegetation is the same, the human heat load is the same in areas with different geographical locations but the same climate. This is valid – of course – on biome, global scale. This makes sense to us, so we didn't include this overly long explanation, which doesn't fit thematically into the thesis.
The conclusion repeats the results but lacks reflective insight. What are the broader implications for public health, urban design, or forecasting?
ANSWER: Section Conclusion has been rewritten. We don't mention results. We did not discuss the practical applicability of the results, as this topic is not relevant to the subject of our study. We intended the article to be a purely climatological article.
How could this model be integrated into decision-making tools or weather services?
ANSWER: The biggest obstacle in using the model in this way is the simulation of sweating. We are currently working on this, ont he parameterization of sweating.
I hope the authors find these comments constructive for improving the manuscript.
ANSWER: Thank you very much for the comments, we have become much more "aware" by writing the modifications and checking what has been written.
Submission Date
20 March 2025
Date of this review
14 Apr 2025 09:49:49
© 1996-2025 MDPI (Basel, Switzerland) unless otherwise stated
Author Response File: Author Response.pdf
Reviewer 4 Report (New Reviewer)
Comments and Suggestions for AuthorsThis work is entitled “The human thermal climate of mornings with clear skies in the Hungarian lowland”. Before being published, I suggest some improvements.
The abstract should be improved. Add in the beginning a short introduction.
The introduction should be improved. Add more details about the references [9–12], [13–16], [17,18] and others.
The paper should be improved. The nomenclature distributed in the paper should be added at the beginning or the final. Some small errors in the test should be corrected, as “and170” in line 13, “m2” in lines 14 and 15, and …
More details about the PED and UTCI models should be added.
In the materials and methods, for example, in point 2.1, the values of the variable presented in the text should be placed in a table.
More details about the observations should be added.
More details about the selected persons should be added. Add also complementary information about the selection of these persons.
Add a table about the Input of the case studied.
Add more information about the application of this informations in other situations and countries.
More details about the Future works should be added.
The conclusion should be improved.
Author Response
REPLY TO REVIEWERS' COMMENTS
RESPONSES ARE IN RED
REVIEWER-4
Comments and Suggestions for Authors
This work is entitled “The human thermal climate of mornings with clear skies in the Hungarian lowland”. Before being published, I suggest some improvements.
The abstract should be improved. Add in the beginning a short introduction.
ANSWER: The short Introduction is written. The modification is as follows: „The climate of the Hungarian lowland (Central European region, Pannonian Plain area) can be characterized by Köppen's Cfb climate formula (C – warm temperate, f – no seasonality in the annual course of precipitation, b – warm summer). This characterization does not provide information about human thermal load and thermal perception. The aim of this work is to fill this gap. We focused on the morning, clear-sky periods of the day, when the heat supply provided by the weather is the lowest. Human thermal load of clear-sky mornings was estimated by using the new clothing thermal resistance–operative temperature (rcl–To) model. In contrast to IREQ-type (Required Clothing Insulation) models, the model parametrizes the total metabolic heat flux density (M) as a function of anthropometric data (body mass, height, sex, age).”
The introduction should be improved. Add more details about the references [9–12], [13–16], [17,18] and others.
ANSWER: It is done. The modification is as follows: „This study used a climatological approach: the multiannual variation of UTCI and PET was analysed at four Hungarian stations. The studies examine either average [9–11], extreme [12,13], or specific urban microclimate [14-19] conditions. When studying urban microclimate, the issue of human comfort was in the focus. A correlation between severe heat waves and increased mortality has also been observed [20]. The topic of subjective thermal sensation was also investigated [21,22]. These studies did not analyze the effects of human variability on the human thermal load. It should be mentioned that the applications of human biometeorological studies and climate classification methods have developed independently of each other [7,23]. The two approaches were rarely linked [24]. These studies analyzed the frequency of human biometeorological information occurring in climate types [25,26] or compared the spatial distribution of climate types and human thermal loads [10,11]. These studies did not use data characterizing selected weather types, but measured time series [8].”
The paper should be improved. The nomenclature distributed in the paper should be added at the beginning or the final.
ANSWER: We did not add nomenclature because the number of important variables is small. Furthermore, we named all variables as soon as they were introduced.
Some small errors in the test should be corrected, as “and170” in line 13, “m2” in lines 14 and 15, and …
ANSWER: We made the corrections.
More details about the PED and UTCI models should be added.
ANSWER: This work has nothing to do with the PET and UTCI indices beyond the fact that these indices were mentioned in the introduction. That's why we didn't deal with them separately.
In the materials and methods, for example, in point 2.1, the values of the variable presented in the text should be placed in a table.
ANSWER: It is done. BMI has a separate column in the table.
More details about the observations should be added.
ANSWER: It is done. The following two sentences were included: „We did this immediately after the observation. The observations were carried out randomly without prior preparation.” We considered these important.
More details about the selected persons should be added. Add also complementary information about the selection of these persons.
ANSWER: It's not the number of people that matters, but the extent of the differences between people. The differences in BMI and M between these 3 people almost cover the adult database. The impact of human variability on human thermal load was examined in a separate study, cited in the article [41]. Sex was not a consideration when selecting individuals. Our only consideration was that the M and BMI values should be as different as possible. We aimed to ensure that the M and BMI values cover the adult value range of the database as much as possible.
Add a table about the Input of the case studied.
ANSWER: It is in the Supplementary Material.
Add more information about the application of this informations in other situations and countries.
ANSWER: In our opinion, the human thermal load results obtained in the Hungarian lowland with a Cfb climate can be extended to all areas with a Cfb climate, regardless of their geographical location. Based on the insights of Humboldt and Köppen, we can say that areas with the "same" climate also have the "same" vegetation, regardless of their geographical location. At the scale of biomes, vegetation is a climate indicator. Since vegetation is strongly dependent on heat supply, the vegetation of areas with different geographical locations but the "same" heat supply can be considered "the same". Since the environmental (climatic) heat load of humans and vegetation is the same, the human heat load is the same in areas with different geographical locations but the same climate. This is valid – of course – on biome, global scale. This makes sense to us, so we didn't include this overly long explanation, which doesn't fit thematically into the thesis.
More details about the Future works should be added.
ANSWER: Our future work will focus on heat-excess weather conditions, which cannot be simulated without parameterizing sweating. Since this is a completely different line of research, i.e., not related to heat-deficit conditions, we have not mentioned it.
The conclusion should be improved.
ANSWER: The conclusion section has been rewritten. Here it is: „The human thermal load of cloudless mornings observed in the Cfb climate of the Hungarian lowland was characterized by using the rcl–To model. The model simulates personal M values as a function of the person's anthropometric data (body mass, body length, sex, age) for standing or walking humans. The main conclusions of the study are as follows: 1) the morning weather of Cfb climates, when the sky is clear, causes a lack of heat even in the summer. 2) Human variability has a smaller impact on the variability of rcl values than the type of activity. 3) As the heat deficit increases, the interpersonal variability of rcl increases, too, and conversely, as the heat deficit decreases, the interpersonal variability of rcl decreases. 4) Customized individual models are not so complex that they should not be preferred over models that use the concept of a "standard human".”
REMARK: Thank you very much the remarks.
Submission Date
20 March 2025
Date of this review
16 Apr 2025 18:32:31
© 1996-2025 MDPI (Basel, Switzerland) unless otherwise stated
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report (Previous Reviewer 1)
Comments and Suggestions for AuthorsIt can be published
Author Response
The main comment is as follows:
It can be published.
We have no comment on this. Thank you very much.
Reviewer 3 Report (New Reviewer)
Comments and Suggestions for AuthorsThe article has improved considerably. I have nothing further to add.
Author Response
The main comment is as follows:
The article has improved considerably. I have nothing further to add.
We have no comments. Thank you very much the opinion.
Reviewer 4 Report (New Reviewer)
Comments and Suggestions for AuthorsIn the actual version, in general, all suggestions given by the reviewer were commented.
Author Response
The comment is as follows:
In the actual version, in general, all suggestions given by the reviewer were commented.
We have no comment. Thank you very much the opinion.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsAfter careful consideration, I found the manuscript is not suitable for publication in its current form. The decision is based on the following reasons:
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Lack of Novelty: While the manuscript applies established models, such as the IREQ model, the work does not introduce significant methodological advancements. The application of the model is limited to a localized climate, which reduces its broader relevance and impact in the field.
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Insufficient Data and Representation: The study is based on a limited number of observations, which raises concerns about the representativeness of the findings. The data set does not appear robust enough to support the general conclusions drawn by the authors.
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Limited Generalizability: The findings are highly specific to the Hungarian lowland region and may not be applicable to broader geographic or climatic contexts. For a journal with a global readership, we expect research that offers insights of wider relevance.
minor improvement
Reviewer 2 Report
Comments and Suggestions for AuthorsThis is an interesting paper, and discusses the human thermal load of mornings with clear skies during the year in the Hungarian lowland，but the depth of the paper is obviously insufficient, specifically as follows:
[1] Relevant studies are not analyzed in the Introduction, so it is suggested to supplement them and clarify the significance and innovation of this study.
[2] In section 2.3，, it is suggested to elaborate the observation method.
[3] In section 4.1, the headings of Table 1 should be placed above the table. In addition, the paper only selected 3 people for the study, the sample size is too small, and why only male?
[4] Although the results were analyzed in detail, the sample size was too small to draw general rules.
Comments on the Quality of English LanguageMinor editing of English language required.
