Heat Stroke: Cold Weather's Surprising Danger

Heat stroke is a serious health condition that occurs when the body is unable to regulate its core temperature, resulting in a rapid increase in body temperature, failure to sweat, and the inability to cool down. While it is commonly associated with hot and humid weather, it is important to recognize that heat stroke can also occur in cold environments. In cold weather, the body's temperature control system can be overwhelmed, leading to heat-related illnesses such as heat stroke. This is particularly relevant when engaging in physical activity or work in cold conditions, as metabolic heat production increases significantly. Understanding the risk factors and signs of heat stroke in cold weather is crucial to prevent serious health consequences.

Heat stroke can be fatal

Heat stroke is a severe heat illness that can be fatal. It is characterised by a body temperature of over 40°C (104°F), red skin, headache, dizziness, and confusion. It is caused by high external temperatures and/or physical exertion, and is often preventable. However, certain health conditions, medications, and age-related factors can increase the risk of heat stroke.

Heat stroke is a serious medical condition that requires immediate attention. If left untreated, it can lead to vital organ damage, unconsciousness, and even organ failure. The high temperatures and physical exertion overwhelm the body's thermoregulation, leading to a failure of the body's temperature control system. This results in an abnormally high body temperature, which can be life-threatening.

The early symptoms of heat stroke include behavioural changes, confusion, delirium, dizziness, weakness, agitation, slurred speech, nausea, and vomiting. In some cases, seizures and sphincter incontinence have also been reported. It is important to recognise these early signs and take immediate action to prevent further deterioration.

To prevent heat stroke, it is crucial to stay hydrated and avoid excessive heat. Wearing lightweight, light-coloured, loose-fitting clothing also helps. It is recommended to drink plenty of cool liquids and mineral salts to replace fluids lost through sweating. Maintaining a healthy weight and managing any chronic health conditions are also important factors in reducing the risk of heat stroke.

The treatment for heat stroke involves rapid mechanical cooling and standard resuscitation measures. It is important to move the affected person to a cool area, remove unnecessary clothing, and initiate cooling strategies such as spraying the person with water and using a fan, or immersing them in a cold bath. Seeking immediate medical attention is crucial, as any delay in treatment can be fatal.

Heat injuries can occur in winter

In cold weather, the risk of heat injury persists, especially when exercising or working in a hot and humid indoor environment. For example, if you are bundled up and perspiring more than you realise, you can still get heat cramps, heat exhaustion, and heat stroke. Heat injuries occur when your body cannot cool down through sweating, leading to a dangerous rise in core body temperature.

To prevent heat injuries in the winter, it is important to consider the type of clothing you wear. Choose light-coloured, loose-fitting garments, and try to limit yourself to one layer. It is a common misconception that you should wear many layers to stay warm in cold weather, but this can actually increase your risk of heat injury by trapping body heat. Instead, opt for a middle layer of down or wool, which will provide insulation even if it gets wet.

Staying hydrated is also crucial. Drink plenty of fluids before, during, and after any physical activity, and weigh yourself before and after to monitor water loss. Ensure your urine is a light colour—the darker it is, the more dehydrated you are. Additionally, increase your salt intake in the days leading up to any strenuous activity, as salt depletion can lead to muscle cramps.

Finally, listen to your body and be mindful of the common signs of heat injury, such as dark-coloured urine, nausea, dizziness, headache, and rapid pulse. If you experience any of these symptoms, seek medical attention immediately. By taking these precautions, you can help reduce the risk of heat injuries, even in the cooler winter months.

Heat stroke symptoms

Heat stroke is a serious medical condition that requires urgent attention. It is the most severe form of heat-related illness and can be fatal if not treated promptly. Heat stroke occurs when the body is unable to regulate its temperature, resulting in a rapid increase in core body temperature. This can happen in hot and humid weather, but it is important to note that heat stroke can also occur in cold environments, particularly during physical exertion.

The symptoms of heat stroke are:

• A high body temperature of 103°F (39.4°C) or higher
• Hot, red, dry, or damp skin
• Throbbing headache
• Confusion, irrational behaviour, or dizziness
• Nausea
• Shortness of breath
• Convulsions
• Loss of consciousness

If you or someone you know is experiencing these symptoms, it is crucial to act quickly. Move the person to a cooler place, preferably an air-conditioned environment, and help lower their body temperature with cool cloths or a cool bath. Do not give the person anything to drink, and call for emergency medical assistance immediately.

It is important to note that heat stroke can be prevented by taking appropriate precautions, such as wearing lightweight and light-coloured clothing, staying hydrated, and avoiding strenuous activity during the hottest parts of the day. Additionally, acclimatization is crucial; it is advised to allow at least 7 to 10 days for the body to adjust to a new, hotter environment.

Heat exhaustion symptoms

Heat exhaustion is a mild to moderate illness that can occur when the body gets too hot and can't cool itself down. It is often a result of losing too much water and salt, usually due to excessive sweating. Heat exhaustion can occur during or after exertion in hot, humid areas. It is important to recognise the symptoms of heat exhaustion and take appropriate action to prevent progression to heat stroke, a more severe and potentially fatal condition.

The symptoms of heat exhaustion include:

• Weakness
• Dizziness or faintness
• Headache
• Nausea
• Thirst
• Rapid pulse
• Elevated body temperature (38.5–40°C; 101.3–104°F)
• Cool, moist skin with goosebumps
• Rapid, shallow breathing
• Swelling of the ankles, feet, or hands (heat edema)
• Drop in blood pressure when standing

In babies and young children, who are at a particularly high risk of heat exhaustion, the symptoms may include:

• Paler skin than usual, noticeable on the palms, nails, eyes, gums, or tongue
• Cooler than usual skin
• Increased thirst and other signs of dehydration, such as reduced peeing or crying
• Rise in body temperature

If you or someone you know is experiencing these symptoms, it is important to act quickly. Move to a cool, shaded area and rest. Drink water or sports drinks, taking small sips rather than large gulps. Remove any tight or unnecessary clothing. Applying cooling measures such as a cool shower, bath, or sponge bath, or using fans or ice towels, can also help.

If symptoms do not improve within an hour, or if they worsen, seek medical attention. Heat exhaustion can progress to heat stroke if not treated promptly, so it is important to take these symptoms seriously.

Preventing heat stress

While it is more common in hot weather, it is possible to experience heat strain in cold environments. This is due to an imbalance between physical activity, metabolic heat production, and the thermal insulation of clothing. Therefore, it is important to take steps to prevent heat stress, especially when engaging in physical activity outdoors. Here are some ways to prevent heat stress and heat-related illnesses:

Stay Hydrated

Hydration is crucial in preventing heat-related illnesses. Drink plenty of water throughout the day, and if you're going to be outdoors, make sure you're well-hydrated before leaving the house. If you're sweating a lot or exercising outdoors, consider replenishing electrolytes with a sports drink.

Dress Appropriately

Wear light-colored, lightweight, loose-fitting, and water-vapor permeable clothing. Tight-fitting and layered clothing can trap heat and make it harder for your body to cool down. In addition, consider wearing a wide-brimmed hat to protect your head and face from direct sunlight.

Seek Shade and Air Conditioning

When outdoors, seek shade and a cool breeze. If possible, stay indoors during the hottest parts of the day. If you must be outdoors, take frequent breaks in the shade and rehydrate.

Exercise Caution with Physical Activity

Strenuous physical activity can increase your risk of heat stress. If possible, exercise indoors or during the early morning or late afternoon when temperatures are cooler. If you must exercise outdoors, consider reducing the intensity or duration of your workout.

Avoid Hot Cars

The temperature inside a parked car can rise quickly, even with the windows cracked. Avoid staying in a parked car for extended periods, and never leave children or pets unattended in a vehicle, even for a short period.

Limit Alcohol Consumption

Alcohol can impair your body's ability to regulate its temperature. The CDC recommends avoiding alcohol within 24 hours of working or exercising in the heat to reduce the risk of heat illness. Instead, focus on staying hydrated with water.

Use Sweat-Resistant Sunscreen

It is important to protect your skin with sunscreen, even on cloudy days. In hot weather, choose a sweat-resistant or sports-formulated sunscreen, and remember to reapply as indicated on the bottle, especially after sweating or swimming.

Know the Signs of Heat-Related Illnesses

Educate yourself about the signs and symptoms of heat exhaustion and heat stroke. If you or someone around you is showing signs of heat-related illnesses, take immediate action to cool down and seek medical attention if necessary.

Additional Considerations for Employers

If you are an employer, it is important to take steps to reduce workplace heat stress. This can include engineering controls such as increasing air velocity or using reflective shielding. Work practice recommendations include limiting time in the heat, reducing physically demanding tasks, providing adequate cool water near the work area, and encouraging workers to take breaks and stay hydrated.

Frequently asked questions