Heat waves and health: an observational study on heat related illnesses among medical students in north Karnataka

INTRODUCTION

Heat related disorders, which can vary from minor ailments like heat cramps to deadly conditions like heat stroke, pose a major threat to millions of people worldwide. Heatstroke, a more serious condition, is indicated by a body temperature of 40-degree Celsius or above along with CNS dysfunction. Among its potentially fatal symptoms include multiorgan failure, hypotension and tachycardia. Moreover hallucinations, seizures and delirium are also symptoms associated with HRIs.¹

According to World Health Organization, if a stations temperature hits 40 degree Celsius or higher for the plains and 30 degrees Celsius for the hilly areas, a heat wave is declared in India. In India, heatwaves usually last from March to June, and they can occasionally last up to July. The country’s northern regions experience five to six heat wave episodes annually on average.² A recently developed area of study within the subject of research on climate change that is highly relevant to society as a whole is heat wave research.³

Globally there is an increasing concern about extreme weather occurrences particularly heat waves. Recent weather events have exceeded earlier predictions that global warming would reach 1.5-degree Celsius higher than pre industrial levels from 2030 to 2052. The worldwide average temperature threshold briefly went above the 1.5-degree Celsius threshold for the first time in 2024, according to data from world meteorological organisation and Copernicus climate change service. The negative impacts of heat waves are exacerbated by their persistence, which has direct and cumulative effects on human health.⁴

Over 166,000 people died as a result of heatwaves globally between 1998 and 2017, with roughly 70,000 of those deaths occurring in Europe and roughly 55,000 in Russia in 2010. Globally, the number of individuals exposed to heatwaves increased by over 125 million between 2000 and 2016. Heat waves increase risk to public health by exacerbating pre-existing chronic ailments like cardiovascular, respiratory, renal, diabetic, and mental health disorders in addition to their direct effects like heatstroke.⁵

Even though there are many studies on the health risks of heatwaves around the world there is still a lack of studies in India, particularly in the state of Karnataka, and a substantial information gap about the precise effects of heatwaves on public health exists.⁶ Family adoption program (FAP) is suggested by the (NMC) which is the National Medical Commission of India as part of the MBBS curriculums competency based medical education (CBME). Through community involvement, students can observe directly the conditions of living in those they treat as hospital patients. Additionally, students learn how different health issues affect patients in real world situations.⁷ During these outreach programs like FAP, surveys, field visits medical students are vulnerable to heat stress and heat related illnesses. This study was designed to elicit the perception regarding heat related illness among medical students.

METHODS

Study area

This study was done among medical students in BLDE (DU) Shri B. M. Patil Medical College Hospital and Research Centre, Vijayapura, Karnataka, India.

Study period

The study was done for a period of 2 months from April 2024 to May 2024.

Study design and participants

The study design involved a cross-sectional study and was done among medical students. The sample size was determined based on mean±SD of Knowledge score of heat related illness among military personnel 9.04±1.832 with reference to a study done by Al Johani et al.¹ considering 95% confidence interval and 0.2 precision. The sample size obtained was 325 medical students.

Inclusion criteria

Medical students who consented to participate were recruited in this study and who had completed at least 6 months of MBBS course in this study area were chosen.

Exclusion criteria

Medical students who were did not consent to be part of the study were excluded. Medical students who already had dermatological problems and any form of physical disability were also excluded.

Data collection

A semi-structured, self-administered questionnaire was used to gather data, which assessed the perception regarding heat stress and heat related illness, among medical students and the questionnaire was distributed as a Google form. We collected data from 325 medical students and the students were selected using simple random sampling technique.

Before commencing data collection, the recruits were given a briefing regarding the purpose of the study, its objectives, benefits. An informed verbal consent was obtained from each participant who volunteered to be part of this study. Socio demographic profile, knowledge, attitude and practice regarding HRIs was gathered from medical students.

Data analysis

The data was represented using numbers, percentages and chi square tests. The results were presented in tabular form and in figures for clarity and ease of representation. The key to data analysis was the statistical package for the social sciences software (IBM SPSS Statistics for windows, IBM Corp. version 26.0)

Ethical clearence

BLDE (DU) Shri B. M. Patil Medical College Hospital Vijayapura provided institutional ethical clearance with IEC number BLDE (DU)/IEC/1100/2023-24.

RESULTS

The sociodemographic profile of the 325 MBBS students is shown in Table 1. Most participants were in the age group 22 to 25 years (n=233, 71.7%) and majority of the participants were females (n=172, 52.9%). The major share of the medical students hailed from urban area of residence (n=286, 88%). Second year (MBBS) medical students accounted for the maximum number of participants who willingly enrolled for this study (n=91, 28%). Religious classification of the students revealed that Hindus were the predominant group (n=282, 86.8%).

Medical students’ responses to questions about their understanding of this topic are shown in Table 2. The study revealed that 83% of medical students recognized the danger of heat related illnesses and that it can lead to fainting while on field work.

Eighty three percent of respondents agreed that patients suffering from heat exhaustion or heat stroke were treated with icepacks, fluids, transportation to a colder location.

More than 81% of MBBS students opined that the common symptoms of heat exhaustion or heat stroke were fever, fatigue and chest pain. According to over 81% of MBBS students, fever, weariness, and chest pain are typical signs of heat exhaustion or heat stroke. The percentage of responders who thought that wearing thick garments avoided heat exhaustion or heat stroke was just 22%. According to three-quarters of the respondents, if heat stroke is suspected, the victim should be moved to a colder location before an ambulance is dispatched. When working in the field, 82% believe that muscle contractions can occur due to heat related illnesses. Heat exhaustion or heat stroke can be averted by cooling the body as opined by the majority 83%. Seventy five percent of respondents believed that residing in cold climates could prevent heat stroke. According to 91% of respondents said that perspiration did, in fact, reduce body temperature. Just 28% of respondents agreed that only physically weak individuals were vulnerable to heat related illnesses during heavy field work, while 72% disagreed. When asked if heat related illnesses may cause a quick death when working in the field areas, 74% of research participants agreed, while 24% disagreed. 75% of medical students correctly identified a body temperature exceeding 40-degree Celsius as the cause of heat exhaustion or heat stroke.¹

The participants identified sweating (62%), lack of sweating (32%), defecation (6%) as symptoms of HRI’s that were commonly seen during field work. Medical students selected oral rehydration solution (78.5%), water (19%) and soft drinks (2.5%) as the preferred drink to give to a person exhausted due to heat or heat stroke. The following risk factors were enlisted by the participants which accentuates heat related illnesses during field duty, such as drinking alcohol (43.1%), age factor (28.6%), weight gain (19.4%), not drinking enough fluids (8.9%). To protect themselves from heat related illnesses during field work, the medical students advocated drinking enough fluids (79.7%), wear thick and dark clothes, use sunscreen (14.5%). When asked what kind of thermal disease was the most dangerous, the replies varied like, heat stroke (74.5%), heat exhaustion (11.6%), thermal fainting (10.5%), and heat cramps (3.4%) (Table 2).¹

When the medical students were asked if they would take preventive measures against heat cramping, heat exhaustion and heat stroke before and during field work if a high temperature warning was sounded, the response was as follows, sometimes (51.1%), much 43.1%), not at all (5.8%). As to how concerned were they about the risk of heat illness during field work, 44% were very concerned, 37.8% was a little concerned and 4% was not at all concerned. When the subjects were asked if they considered themselves sensitive to extreme heat, 45.2% were somewhat concerned, 32% were very much concerned, 13.5% didn’t know, 6.5% said not at all and 2.8% said too little concerned. Whether they thought that doctors were raising sufficient awareness of the risk of heat related diseases, 54.5% thought that just enough awareness was raised, whereas 37.8% didn’t know and 7.7% opined that too much awareness was raised by concerned doctors (Table 3).¹

Only 43.7% of medical students were of the opinion that authorities managed field activities at a relatively cooler time when a temperature warning was issued. 46.8% of students said that before going out for field visits, the college authorities or teachers told them of ways to protect against heat related illnesses. Medical students were asked if their teachers or staff members prepare adequately to treat heat related illnesses when they went for field work, only 47.4% replied in the affirmative. Surprisingly only 16.3% of the medical students paid attention to the signs and symptoms of heat cramps, heat exhaustion and heat stroke. Alarmingly only 26.8% of medical students drank water when they felt thirsty during field visits. One fifth of the students, 22.8% were prepared well to treat heat related illnesses with resources such as fluids, when they went for field visits (Table 3).¹

Total KAP score was calculated from a minimum score of 7 and a maximum of 27, with mean of 19.43 and a standard deviation of 3.676. Knowledge score, minimum score was 4, whereas the maximum score was 18, mean 14.12 with a standard deviation of 2.652. Attitude score, minimum was 0, maximum score was 4 with a mean of 1.81 and standard deviation of 1.194. Practice score, minimum score was 0, maximum was 6, mean of 3.50 and standard deviation of 1.535 (Table 4).

A score of more than or equal to 80% was considered good, whereas a score less than 80% to more than or equal to 50% was deemed poor and a score of less than 50% was recorded as poor.

Considering the proportion of the level of KAP, 52% had good knowledge, 36% had average and 12% had poor knowledge. Only 31% had good attitude, 24% had average attitude and 45% had poor attitude. 34% had poor practice, 38% had average practice, and 28% had poor practice with respect to heat related illnesses.

On studying the association between sociodemographic profile age with knowledge score with respect to age, p value was 0.603 and was not statistically significant. Gender with knowledge score p value was 0.04* which is statistically significant. Residence to knowledge score association, p value was 0.1. Association between knowledge score and education was 0.02*. Association between attitude score and age, p value was 0.063. Association between gender and attitude score, p value was 0.006*. Association between residence and attitude score, p value was 0.86. Education and attitude association, p value was 0.01*. Age to practice score, p value was 0.764, knowledge score to gender p value was 0.03*. Residence to practice score, p value was 0.81. Education to practice score, p value was 0.02* (Table 5).

*Statistically significant.

DISCUSSION

Considering the proportion of the level of KAP, 52% of medical students who participated in this study had good knowledge, 36% had average and 12% had poor knowledge. Only 31% had good attitude, 24% had average attitude and 45% had poor attitude. 34% had poor practice, 38% had average practice, and 28% had poor practice with respect to heat related illnesses.

In a study done by Al Johani et al in Saudi Arabia among military personnel, the sample size was 168.¹ They had good knowledge (mean 9.04/13), 81% had good attitude, 75.6% were attentive to symptoms, mean knowledge score was 9.04±1.83, mean attitude score was 9.61±2.41, mean practice score was 3.39±1.70. 89.9% participants drank enough fluids. 64.9% felt that the awareness given by doctors regarding heat related illnesses was insufficient.

In a study conducted by Wang et al in China among 640 military personnel who were exposed to hot climate during their training, had a mean knowledge score of 10.37 (range 3-13: SD 1.63, mean attitude score of 7.76 (range 0-16; sd 2.65), mean practice score 3.80 (range 1-6:SD 1.12).⁸ Overall knowledge score was high, had very poor score on exertional heat stroke.

A study by Alebaji et al with 402 participants 58% drank water only when thirsty.⁹ 32% was unaware of the harm posed by heat stroke. 44% were unaware that water should be given to victim.

In a study done by Ramakrishnan et al, a study done among brickkiln workers in Puducherry India, 68.2% of subjects never had any heat related illnesses, whereas 11.4% had experienced HRIs.¹⁰ Knowledge score, attitude score and practice scores were 13.5 (SD±4.01), 4.21(SD±2.17), and 4.23 (SD±1.99).

In a study conducted by Sharma et al, in Nepal, just over half (57%) of the study’s participants were men, and their average age was 37.2 years (SD±10.5). They had worked outside for an average of 10.7 years (SD±10.5). They had worked outside for an average of 10.7 years (SD±8.6). Of all participants, 86.2% were aware of heat related incidents, 43% had heard of heatwaves, and 78.6% had firsthand experience with them. For the entire sample, awareness of heatwaves was positively correlated with heat protective practices (practice score =1.46, p=0.001). Heat protection practices were found to be inversely correlated with age (practice score =-0.03, p=0.001). Males practiced less heat prevention than females (practice score =-0.97, p<0.001).¹¹

Another cross-sectional study done in China by Zhang et al, from December 10^th 2023 to march 21^st 2024 in Ningbo city, the survey revealed several significant gaps in knowledge of specific risk factors and preventive actions, even though Ningbo population had adequate overall comprehension of heat stroke. The results recommended customised health education programs to encourage community wide awareness and prevention, especially for youth and communities with lower levels of education.¹²

In another study done by Hasan et al, the conclusion was that heat action plans, which involve establishing early warning systems, developing local capacity to recognise, prevent, or treat and manage heat related illnesses, and disseminating information. Have demonstrated encouraging outcomes in lowering heat related mortality and morbidity.¹³

In a study by Xu et al, the results showed that the general public has adequate knowledge, proactive behaviours, and active attitudes towards heatstroke. To further improve their KAP toward heatstroke, educational programs and interventions must be developed and put into action.¹⁴

In a study by Li et al, in order to help kids and their parents better adapt to heatwaves and climate change, a primary school heat and health education program was a successful strategy. Heatwaves and other extreme weather or climate events in the context of climate change, as well as other emergent situations or public health education, such as the control and prevention of COVID-19.¹⁵

Nowrouzi-Kia et al, in a study mentions that results from south Australia show that there is a four-to-seven-fold increase in claims for occupational heat illness during heatwaves compared to non-heatwave periods.¹⁶

This study has some limitaions. This study was done in single centre, which was a tertiary care centre. Sample size was calculated based on a similar study and was 325 participants. More samples would have made the study more generalizable. The study group was medical students and we could have included other medical professionals like nursing, working doctors, post graduates and allied health students. The level of exposure to heat related illnesses during field visits varied between the phase of MBBS the students were involved in.

CONCLUSION

Considering the proportion of the level of KAP, 52% of medical students who participated in this study had good knowledge, 36% had average and 12% had poor knowledge. Only 31% had good attitude, 24% had average attitude and 45% had poor attitude. 34% had poor practice, 38% had average practice, and 28% had poor practice with respect to heat related illnesses. Precise protocols and guidelines need to be developed to improve the readiness in tackling heat related illnesses. Feedback from students need to be collected by the administration to enact new policies that can ensure that field visits are rescheduled based on climate warnings. Greater synergy between medical students, community medicine department staff and medical college administration in enacting proper environment friendly practices and adopting uniforms that are protective against extreme heat.

Recommendations

Proper scheduling of field visits for community medicine students who are participating in family adoption programme must be scheduled based on the weather reports. Heatwaves and extreme weather conditions should make the authorities reschedule the field visits to more environment friendly timescale. Proper arrangements for transportation in buses should be arranged and students should be advised to wear uniforms that offer protection from heat. Wearing hats should be made mandatory; students should be advised to carry umbrellas and have sufficient clean drinking water. Medical treatment should be given to students who faint or show signs of heat stress. Emergency medical kits should be available for prompt use in case of emergencies. More studies should be conducted regarding heat related illnesses among varied sections of the society.

ACKNOWLEDGEMENTS

The authors express their gratitude to all the 325 medical students who participated in this study. The authors also express gratitude to guides and mentors from the Department of Community Medicine.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee BLDE (DU) Shri B M Patil Medical College Hospital and Research Centre. BLDE(DU)/IEC/1100/2023-24

REFERENCES

1. 1. Al Johani RA, Marzook NT. Knowledge, attitudes, and practices of military personnel regarding heat-related illness. Cureus. 2023;15:e49821.
2. 2. World Health Organization. Heat waves. New Delhi: WHO India. Available from: https://www.who.int/india/heat-waves. Accessed on 24 February 2026.
3. 3. Marx W, Haunschild R, Bornmann L. Heat waves: a hot topic in climate change research. Theor Appl Climatol. 2021;146(1-2):781-800.
4. 4. Freitas F de, Fogagnolo C, Dornfeld RL, Vitolo MR, Antônio MÂ, Brandão MÂB. Environmental health during extreme heat: challenges for the practice of safe physical activity in childhood and adolescence. Cad Saude Publica. 2026;42:e00131825.
5. 5. Hundessa S, Huang W, Xu R, Yang Z, Zhao Q, Gasparrini A, et al. Global excess deaths associated with heatwaves in 2023 and the contribution of human-induced climate change. Innovation. 2025;6(10).
6. 6. Thakkar V, Srinivas V, Marula Siddhappanavara P, Madappa T, Jeganathan A, Murthy IK. Heatwave health risk index for Karnataka, India. J Clim Chang Health. 2025;22:100428.
7. 7. Ganganahalli P, Yankanchi SG, Yadavannavar M, Udgiri R. Perception and impact of the family adoption program (FAP) among Indian medical students: benefits and challenges. Cureus. 2024;16:e73893.
8. 8. Wang X, Xia D, Long X, Wang Y, Wu K, Xu S, et al. Knowledge, attitudes, and practices of military personnel regarding heat-related illness risk factors: results of a Chinese cross-sectional study. Front Public Health. 2021;9:707264.
9. 9. Alebaji MB, Elzini TH, Shahin HBA, Suleiman ABM, Richard H, Dali RIA. Knowledge, prevention, and practice of heat strokes among the public in United Arab Emirates (UAE). Int J Med Stud. 2022;10(2):175-9.
10. 10. Ramakrishnan I, Senthil R, Pravinraj S, Dhasaram P, Venkatesan M, Manjubairavi T, et al. Risk perceptions of heat-related illnesses, assessing vulnerability, and adaptive capacity of brickkiln workers in a rural Puducherry: a cross-sectional study. Indian J Community Fam Med. 2025;11(1):8-13.
11. 11. Sharma S, Marasini S, Joshi A, Dangaura NR, Timsina LR, Guragain D, et al. Exploring outdoor workers' knowledge, attitudes, practices, and perceived risks of heatwaves in Nepal. PLoS One. 2025;20(8):e0329557.
12. 12. Zhang W, Feng Y, Chai S, Yang Z, Dong J. Public knowledge, attitudes, and practices toward heat stroke in Ningbo, China: A cross-sectional study. Front Public Health. 2025;13:1659132.
13. 13. Hasan F, Marsia S, Patel K, Agrawal P, Razzak JA. Effective community-based interventions for the prevention and management of heat-related illnesses: a scoping review. Int J Environ Res Public Health. 2021;18(16):8362.
14. 14. Xu Y, Chen J, Du J, Jin Y. Knowledge, attitudes, and practices among the general community population toward heatstroke. Front Public Health. 2024;12:1373025.
15. 15. Li Y, Sun B, Yang C, Zhuang X, Huang L, Wang Q, et al. Effectiveness evaluation of a primary school-based intervention against heatwaves in China. Int J Environ Res Public Health. 2022;19(5):2532.
16. 16. Nowrouzi-Kia B, Choi C, Premji R, Sathananthan A, Balakrishnar K, Haritos A, et al. The impacts of climate change on occupational health and work among outdoor workers: a scoping review. PloS Glob Public Health. 2026;6(2):e0005888.