EFFECTS OF HEAT STRESS-HEAT STROKE, HEAT EXHAUSTION

Heat stress is the burden or load of heat that must be dissipated if the body is to remain in thermal equilibrium. The factors which influence heat stress are metabolic rate, air temperature, humidity, air movement and radiant temperature.

1. EFFECTS OF HEAT STRESS PRESENTER - MODERATOR- DR SHEEZA SHAIKH DR KAJAL SRIVASTAVA COMMUNITY MEDICINE PROFESSOR , COMMUNITY MEDICINE

2. Heat stress is the burden or load of heat that must be dissipated if the body is to remain in thermal equilibrium. The f actors which influence heat stress are metabolic rate, air temperature, humidity, air movement and radiant temperature. The amount of heat gained by the body must be equalled by the amount of heat lost from it. Reference -Park’s textbook of preventive and social medicine HEAT STRESS

3. The number of people exposed to extreme heat is growing exponentially due to climate change in all world regions. Heat-related mortality for people over 65 years of age increased by approximately 85% between 2000–2004 and 2017–2021 Between 2000–2019 studies show approximately 4,89, 000 heat-related deaths occur each year, with 45% of these in Asia and 36% in Europe. In Europe alone in the summer of 2022, an estimated 61,672 heat-related excess deaths occurred . High intensity heatwave events can bring high acute mortality; in 2003, 70,000 people in Europe died as a result of the June–August event. In 2010, 56,000 excess deaths occurred during a 44–day heatwave in the Russian Federation. DEMOGRAPHIC DATA REFERENCE-https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health

4. EFFECTS OF HEAT STRESS (1) HEAT STROKE: This is attributed to failure of the heat regulating mechanism. It is characterized by very high body temperature which may rise to 110°F (43.3°C) and profound disturbances including delirium, convulsions and partial or complete loss of consciousness. The skin is dry and hot. Classically, sweating is absent or diminished, but many victims of clear-cut heat stroke perspire profusely. The Outcome is often fatal, even when patients are brought quickly to medical attention: death/case ratios of 40 per cent or more have been reported.

5. The treatment consists of rapidly cooling the body in ice water bath t ill the rectal temperature falls below 102°F (38.9°C). The rectal temperature should be monitored continuously Further treatment is supportive and directed towards the many potential complications of hyperthermia. Hypovolaemia , H yperkalaemia , bleeding Rhabdomyolysis, H ypocalcaemia and diathesis may require intensive supportive treatment. The patient should be kept in bed for several days until the temperature control becomes stable.

6. (2) HEAT HYPERPYREXIA This is attributed to impaired functioning of the heat-regulating mechanism but without characteristic features of heat stroke. It is arbitrarily defined as a temperature above 106°. It may proceed to heat stroke.

7. (3) HEAT EXHAUSTION Unlike heat stroke, near exhaustion is not because of failure of thermo-regulation. It is a milder illness than heat stroke and is caused primarily by the imbalance or inadequate replacement of water and salts lost in perspiration due to thermal stress. Heat exhaustion typically occurs after several days of high temperature. Body temperature may be normal or moderately elevated, but it is uncommon to exceed 102°F (38.9°C).

8. 4) HEAT CRAMPS Heat cramps occur in persons who are doing heavy muscular work in high temperature and humidity. There are painful and spasmodic contractions of the skeletal muscles. The cause of heat cramps is loss of sodium and chlorides in the blood .

9. (5) HEAT SYNCOPE This is a common ill-effect of heat. In its milder form, the person standing in the sun becomes pale, his blood pressure falls and he collapses suddenly. There is practically no rise in body temperature. The co ndition results in lowering of blood pressure and lack of blood supply to the brain. This condition is quite common among soldiers when they are standing for parades in the sun. Treatment is quite simple. The patient should be made to lie in the shade with the head slightly down; recovery usually comes within 5 to 10 minutes.

10. 6)HEAT RASH - Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. Symtoms - Red bumps on skin, usually appears in the area where the clothing is restrictive Sweat ducts plugs, sweat cannot freely evaporate from the skin Treatment Keep skin dry Apply calamine lotion Sleep in cool location Cleanse the skin Wear cotton cloths

11. SEVERITY Less Severe - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - More Severe Discomfort - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Death

12. Brain H igh heat exposure can lead to cognitive dysfunction, like confusion or memory loss. Research shows it can also worsen some mental health conditions Heart Extreme heat puts strain on the heart by making it work harder — and can lead to heat exhaustion or heat stroke if your cardiovascular system can’t properly regulate your internal body temperature. Kidneys If you get dehydrated because of extreme heat, that can lower your kidney function and puts you at a higher risk of kidney injury. Lungs Breathing in high heat can affect lung function, causing inflammation, while also flaring up any existing lung conditions, like asthma or COPD Skin Extreme heat conditions can cause an itchy skin rash. More critically, a combination of high heat and humidity makes it harder for your body to properly sweat to cool itself — which can hike your risk of overheating. REFERENCE-https://www.cbc.ca/news/health/extreme-heat-affects-human-body-

13. If the main symptoms are neglected like hot dry skin confusion, convulsions and eventual loss of consciousness, This is the most severe disorder and can result in death if not detected at an early stage . WHY IT IS AN EMERGENCY

14. Climatic Conditions - Heatwaves and high humidity levels are natural causes. This can be either from the regular hot season, a hotter than usual summer or an especially hot day during summer. Occupational Exposure - Certain jobs, like construction, agriculture, and factory work, often involve working in hot environments. Inadequate Hydration - Not drinking enough fluids during high temperatures can lead to dehydration, exacerbating heat stress. CAUSES OF HEAT STRESS

15. Lack of Acclimatisation - Individuals not accustomed to high temperatures are more susceptible. Clothing  – Employees should avoid wearing extra layers of clothing and clothing that absorbs heat. Poor Ventilation - Environments or workplaces with inadequate air circulation can trap heat, increasing the risk and raising the indoor temperature

16. Examples of workplaces where people might suffer from heat stress due to hot environments created by the process, or restricted spaces, are: C ompressed-air tunnels P ower plants Fo undries and smelting operations B rick-firing and ceramics plants B oiler rooms B akeries and catering kitchens G lass and rubber manufacturing plants L aundries Where does heat stress occur?

17. (1) REPLACEMENT OF WATER Persons working under conditions of high temperature and humidity should be encouraged to drink cool water. It has been found in India that a man doing hard work in the sun requires about one litre of water per hour. For a sedentary worker, the requirement is nearly half this quantity. There is a widespread belief that extra salt intake during the summer helps prevent the ill-effects of heat. However, extra salt is needed by unacclimatized persons during the first ten days of their exposure to heat . PREVENTIVE MEASURES

18. (2) REGULATION OF WORK The duration of exposure to a hot environment should be cut down. There should be periods of rest in between intense work. If signs, such as headache and dizziness appear, the person should be removed to a cooler environment, and the necessary treatment given. (3) CLOTHING The clothing worn should be light, loose and of light colors. (4) PROTECTIVE DEVICES Protective goggles, shields and helmets are helpful. (5) WORK ENVIRONMENT The temperature and humidity in the work environment may be controlled by proper ventilation and air conditioning. Reference -Park’s textbook of preventive and social medicine

19. (6)STAY OUT OF THE HEAT Avoid going outside and doing strenuous activity during the hottest time of day. Stay in the shade. Remember that perceived temperatures in the sun can be 10–15 ˚C higher. Spend 2–3 hours during the day in a cool place. Be aware of the risk of drowning. Never swim alone. Stay informed about official heat warnings

20. (7)Keep your home cool Use the night air to cool down your home by opening windows after dark when the outdoor temperature is lower than the indoor temperature. During the day when outdoor temperatures are higher than indoors, close windows and cover them with blinds or shutters to block direct sunlight. Turn off as many electrical devices as possible. Use electric fans only when temperatures are below 40 ˚C / 104 ˚F. If using air conditioning, set the thermostat to 27 ˚C / 81 ˚F and turn on an electric fan –this will make the room feel 4 ˚C cooler.

21. (8)Keep your body cool and hydrated Use light and loose-fitting clothing and bed linens. Take cool showers or baths. Wet your skin using a damp cloth, spray, or wet light clothing. Drink water regularly (1 cup of water per hour and at least 2–3 litres per day). Regularly check in with vulnerable people in your circle – especially people over 65 years old and those with heart, lung or kidney conditions, a disability, and living alone

22. (9)Protect infants and children Never leave children in parked vehicles for any amount of time, as temperatures can quickly become dangerously high. Avoid direct exposure to the sun during peak hours, seeking shade or staying indoors instead. Shade can reduce how hot you feel by more than 10 °C. Never cover an infant stroller / pram with dry fabric – this makes it hotter inside the carriage. Instead , use a wet, thin cloth and re-wet as necessary to lower the temperature. Combine with a portable fan for even greater cooling. Dress children in lightweight, loose-fitting clothing that covers their skin, and use wide-brimmed hats, sunglasses and sunscreen to protect them from the sun’s rays.

23. The National Institute for Occupational Safety and Health (NIOSH) is the federal institute responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention (CDC), in the Department of Health and Human Services (DHHS). OSHA-NIOSH Heat Safety Tool App- is a useful resource for planning outdoor work activities based on how hot it feels throughout the day. It has a real-time heat index and hourly forecasts specific to your location.Also shows Signs and symptoms and first aid for heat-related illnesses. It also provides occupational safety and health recommendations from OSHA and NIOSH.

24. New Delhi recorded its highest temperature ever measured on Wednesday — 126 degrees Fahrenheit, or 52.3 degrees Celsius  Reference-https://www.nytimes.com/2024/05/29/world/asia/india-delhi- hottess India saw 56 heat-related deaths, nearly 25,000 heat stroke cases from March to May, shows govt data. At 14, Madhya Pradesh reports highest number of deaths due to heat-related illnesses, followed by Maharashtra at 11. MP also recorded most suspected heat stroke cases at 6,584. Reference-THE PRINT news Heat kills more than 50 people in India in three days, Around  33 people died  in the northern state of Uttar Pradesh over the weekend due to the heat, In Odisha (Orissa) state, about  20 people died due  to heat stroke, Reference- BBC News, Delhi

25. REFERENCES- Park’s textbook of preventive and social medicinehttps://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health https://www.cbc.ca/news/health/extreme-heat-affects-human-body-1.6918886#:~:text=Scientists%20say%20it%27s%20because%20high%20temperatures%20have%20a,those%20impacts%20are%20felt%20from%20head%20to%20toe.

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