What is the least severe from heat illness?

Cal/OSHA investigations (Study 2) that in 2006 18% of the suspected victims of heat illness died, and 42% required hospitalization for more than 24 hours.

Cal/OSHA investigations showed that 52% of the suspected victims of heat illness died, and 32% required hospitalization for more than 24 hours.

What is Heat Illness?

T8CCR 3395(b) Definitions defines “Heat Illness” as the following:

"Heat Illness" means a serious medical condition resulting from the body's inability to cope with a particular heat load, and includes heat cramps, heat exhaustion, heat syncope, and heat stroke (see T8 CCR Section 3395).

Heat Illness – "More to the Story"

What Happens to the Body

Human beings need to maintain their internal body temperature within a very narrow range of a few degrees above or below 98.6° F. People suffer from heat illness when their bodies are not able to get rid of excess heat and properly cool. The body losses it's "heat balance" because it can not shed heat at a fast enough rate.

When the body starts to overheat the blood vessels get bigger and the heart beats faster and harder. More blood flows to the outer layers of the skin from the internal "core" so that the heat can be released into the cooler outside environment. If this process does not cool the body fast enough, or the outside air is warmer than the skin, the brain triggers sweating to cool the body. Sweat glands in the skin draw water from the bloodstream making sweat. The sweat evaporates and releases the heat from the body. During an hour of heavy work in hot weather, the body can easily sweat out one quart of water.

Shifting blood to outer body layers (the "shell") causes less blood to go to the brain, muscles, and other organs (the "core"). Prolonged sweating can deplete the body of water and salt causing dehydration. Because the body looses water and the salts that are needed for the muscles to work, muscle cramping may occur. The physiological strain on the body from heat illness may cause the person to become dehydrated, weak, tired, and confused.

As dehydration gets worse the body can no longer keep its temperature within the normal range, sweating stops and severe heat illness occurs. In heatstroke, the person’s body temperature rises rapidly damaging the brain, muscles and vital organs causing death.

Warning

Rapid Onset

Heat illness can develop very rapidly and is not always obvious before it becomes life-threatening. During high heat, heat illness can develop faster and even employees who have been doing their job for sometime are a risk.

Warning

Variability in Symptom Recognition and Reporting

The symptoms of heat illness may vary between individuals. Also, employees may not accurately recognize and report the symptoms. As a result victims may be placed at a greater health risk. A person certified to provide first aid should be available at the work site to initially evaluate potential heat illness victims. See Emergency Response Procedures

Victims of heat illness may not report the full range of symptoms they are feeling because they:

• Choose not to for fear of negative consequences
• Deny that the symptoms may be serious
• Have not been trained to identify the symptoms of heat illness
• Are not physically able to report (e.g., they may have fainted)
• Are not fully aware of what is happening to their bodies (e.g., they may be delirious or mentally confused)

Types of Heat Illness and Common Signs/Symptoms

Heat illness affects the body, causing employees with mild symptoms to experience weakness, tiredness, and mental confusion, or even exhibit irritable or erratic behavior. Heat illness can also affect employees work performance and increase their risk of having accidents.

Warning

Employees should be encouraged never to discount any discomfort or symptoms they are experiencing when working in heat, after work or before the next workday. Heat illness symptoms can occur even after work has stopped. They should immediately report any problems they are experiencing to a supervisor and coworker, or a family member to seek prompt medical attention. Employees and supervisors must be fully trained on the prevention of heat illness before they are assigned to work in locations where they are at risk for heat illness.

Heat illness can be one or more of the following medical conditions including: heat rash, heat cramps, fainting, heat exhaustion, and heatstroke. The following symptoms are commonly associated with the different heat illness medical conditions. Given the variability in recognition and reporting of heat illness symptoms, the information listed below should be used only as a general guideline to train employees and supervisors.

Heat Rash (Prickly Heat) - Heat rash is a skin irritation caused by excessive sweating and clogged pores during hot, humid weather.

General Symptoms:

• Can cover large parts of the body
• Looks like a red cluster of pimples or small blisters
• Often occurs on the neck, chest, groin, under the breasts, or in elbow creases
• Uncomfortable so it can disrupt sleep and work performance
• Complicated by infections

Heat Cramps - Heat cramps affect people who sweat a lot during strenuous work activity. Sweating makes the body loose salts and fluids and minerals. If only the fluids are replaced and not the salts and minerals painful muscles cramps may result.

General Symptom:

• Painful muscle spasms in the stomach, arms, legs, and other body parts may occur after work or at night

Fainting (Heat Syncope) - Employees who stand for long periods or suddenly get up from a sitting or lying position when working in the heat may experience sudden dizziness and fainting. In both cases, the fainting is caused by a lack of adequate blood supply to the brain. Dehydration and lack of acclimatization to work in warm or hot environments can increase the susceptibility to fainting. Victims normally recover consciousness rapidly after they faint.

General Symptoms:

• Sudden dizziness
• light-headedness
• unconsciousness

Heat Exhaustion

Heat exhaustion is the body’s response to an excessive loss of the water and the salt contained in sweat.

Warning

Cool skin temperature is not a valid indicator of a normal body temperature. Although the skin feels cool the internal body temperature may be dangerously high and a serious medical condition may exist.

General Symptoms:

• Heavy sweating
• Painful muscle cramps
• Extreme weakness and/or fatigue
• Nausea and/or vomiting
• Dizziness and/or headache
• Body temperature normal or slightly high
• Fainting
• Pulse fast and weak
• Breathing fast and shallow
• Clammy, pale, cool, and/or moist skin

Heatstroke

Warning

Heatstroke is usually fatal unless emergency medical treatment is provided promptly.

General Symptoms:

• No sweating because the body cannot release heat or cool down
• Mental confusion, delirium, convulsions, dizziness
• Hot and dry skin (e.g., red, bluish, or mottled)
• Muscles may twitch uncontrollably
• Pulse can be rapid and weak
• Throbbing headache, shallow breathing, seizures and/or fits
• Unconsciousness and coma
• Body temperature may range from 102° - 104° F or higher within 10-15 minutes

If the muscles begin to twitch uncontrollably, keep the person from self-injury. Do not place any objects in the mouth.

Monitor body temperature and continue cooling efforts until emergency medical treatment is provided to the victim.

Anyone can suffer from heat-related illness, but those most at risk are:

• People over 65 years, particularly those living alone or without air conditioning
• Babies and young children
• Pregnant and nursing mothers
• People who are physically unwell, especially with heart disease, high blood pressure or lung disease
• People on medications for mental illness.

Elderly people are more prone to heat stress than younger people because their body may not adjust well to sudden or prolonged temperature change. They are also more likely to have a chronic medical condition and be taking medication that may interfere with the body’s ability to regulate temperature.

There are many factors which can cause heat stress and heat-related illness, including:

• Dehydration – to keep healthy, our body temperature needs to stay around 37°C. The body cools itself by sweating, which normally accounts for 70 to 80 per cent of the body’s heat loss. If a person becomes dehydrated, they don’t sweat as much and their body temperature keeps rising.
• Lack of airflow – working in hot, poorly ventilated or confined areas.
• Sun exposure – especially on hot days, between 11am and 3pm.
• Hot and crowded conditions – people attending large events (concerts, dance parties or sporting events) in hot or crowded conditions may also experience heat stress that can result in illness.
• Bushfires – exposure to radiant heat from bushfires can cause rapid dehydration and heat-related illness. Bushfires usually occur when the temperature is high, which adds to the risk.

It is important to know the signs and symptoms of heat exposure and how you should respond. Symptoms vary according to the type of heat-related illness. Babies and young children may show signs of restlessness or irritability and have fewer wet nappies. Older people may become lightheaded, confused, weak or faint.

Some heat-related illness and common symptoms include:

• Deterioration in existing medical conditions – this is the most common health problem of heat stress.
• Heat rash – sometimes called ‘prickly heat’, this is a skin irritation caused by excessive sweating. It can occur at any age, but is most common in young children. It looks like a red cluster of pimples or small blisters. It is most likely to occur on the neck and upper chest, in the groin, under the breasts and in the elbow creases.
• Heat cramps – these include muscle pains or spasms, usually in the abdomen, arms or legs. They may occur after strenuous activity in a hot environment, when the body gets depleted of salt and water. They may also be a symptom of heat exhaustion.
• Dizziness and fainting – heat-related dizziness and fainting results from reduced blood flow to the brain. Heat causes an increase in blood flow to the skin and pooling of blood in the legs, which can lead to a sudden drop in blood pressure. There can be a feeling of light-headedness before fainting occurs.
• Heat exhaustion – this is a serious condition that can develop into heatstroke. It occurs when excessive sweating in a hot environment reduces the blood volume. Warning signs may include paleness and sweating, rapid heart rate, muscle cramps (usually in the abdomen, arms or legs), headache, nausea and vomiting, dizziness or fainting.
• Heatstroke – this is a medical emergency and requires urgent attention. Heatstroke occurs when the core body temperature rises above 40.5 °C and the body’s internal systems start to shut down. Many organs in the body suffer damage and the body temperature must be reduced quickly. Most people will have profound central nervous system changes such as delirium, coma and seizures. The person may stagger, appear confused, have a fit or collapse and become unconscious. As well as effects on the nervous system, there can be liver, kidney, muscle and heart damage.

The symptoms of heatstroke may be the same as for heat exhaustion, but the skin may be dry with no sweating and the person’s mental condition worsens.

Treatment options vary according to the type of heat-related illness. Apply first aid and seek medical assistance immediately if you, or someone you are with, shows any sign of heat exhaustion or heatstroke.

Heat rash – treatment

Treatment for heat rash includes:

• Move the person to a cooler, less humid environment.
• Keep the affected area dry.
• Try using unperfumed talcum powder to increase comfort.
• Avoid using ointments or creams, as they keep the skin warm and moist, and may make the condition worse.

Heat cramps – treatment

Treatment for heat cramps includes:

• Stop activity and sit quietly in a cool place.
• Increase fluid intake.
• Rest a few hours before returning to activity.
• Seek medical help if there is no improvement.

Dizziness and fainting – treatment

Treatment for dizziness or fainting includes:

• Get the person to a cool area and lay them down.
• If fully conscious, increase fluid intake.

Heat exhaustion – treatment

Treatment for heat exhaustion includes:

• Get the person to a cool area and lay them down.
• Remove outer clothing.
• Wet skin with cool water or wet cloths.
• Increase fluid intake if they are fully conscious.
• Seek medical advice.

Heatstroke – treatment

Heatstroke is a medical emergency and requires urgent attention:

• Call triple zero (000) for an ambulance.
• Get the person to a cool, shady area and lay them down while you’re waiting for emergency medical help.
• Remove clothing and wet their skin with water, fanning continuously.
• Do not give the person fluids to drink.
• Position an unconscious person on their side and clear their airway.
• If medical attention is delayed, seek further instructions from ambulance or hospital emergency staff.

Prevention is the best way to manage heat-related illness. Some tips to prevent heat stress include:

• Drink plenty of water – you need to drink more during hot weather, regardless of how active you are, even if you don't feel thirsty (check with your doctor if you are on limited fluids or fluid pills). Avoid alcohol or drinks that contain lots of sugar. Don’t have extremely cold liquids, as they may cause stomach cramps.
• Avoid exposure to heat – stay out of the sun as much as you can,
• Protect yourself outside – if you must be outdoors, remember toprotect yourself from the sun – ‘slip, slop, slap’ by covering exposed skin with lightweight clothes, using sunscreen and wearing a hat, ‘seek’ shade and ‘slide’ on sunglasses.
• Plan ahead – too much activity on a hot day can lead to heat stress. If you can, restrict activity to cooler parts of the day. Avoid physical activities like sport, renovating and gardening.
• Don’t leave kids, older people or pets in cars – even on cool days, cars can heat up to dangerous temperatures very quickly. People or pets that are left unattended in parked cars for even a few minutes are at risk of serious heat-related illnesses and possibly death. Never leave kids, older people or pets in a parked car, even if the windows are left open a fraction.
• Take it easy – rest often and, whenever possible, stay indoors or in the shade.
• Stay cool – and keep air circulating around you. Draw your blinds or curtains and use a fan or air conditioning if possible (if you don’t have air conditioning, consider visiting an air-conditioned shopping centre or public library). Keep yourself cool by using wet towels, putting your feet in cool water and taking cool (not cold) showers.
• Keep up your energy levels – eat smaller meals more often and cold meals such as salads.
• Check in on others – keep in touch with older, sick or frail family, friends and neighbours who may need help coping with the heat, especially those who live alone. Call them at least once on any extreme heat day.

Where to get help

Things to remember

• Heat kills more Australians than any natural disaster.
• Heatstroke is fatal in up to 80% of cases.
• During the 2009 Victorian heatwave the number of deaths increased by 374 people.
• Heat-related illness can be prevented.
• Keep cool, avoid vigorous physical activity in hot weather, and drink plenty of water and other non-alcoholic fluids.
• Never leave children or pets unattended in a parked car.
• Seek medical assistance if a person shows any signs of heat exhaustion or heatstroke.

• Extreme heat and heatwaves, 2015, Department of Health & Human Services, Victorian Government. More information here.
• Extreme heat prevention guide, 2012, US Centers for Disease Control and Prevention. More information here.
• Beat the heat – playing and exercising safely in hot weather factsheet, 2008,Sports Medicine Australia. More information here.
• Bouchama A, Dehbi M, Mohamed G, Matthies F, Shoukri M, Menne B 2007, 'Prognostic factors in heat wave-related deaths: a meta-analysis', Archives of Internal Medicine, vol 167, no. 20, pp 2170-2176. More information here.

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