Heat stroke is one of those conditions that most of us encounter more in movies and TV than in real life. It might be mentioned as one of the dangers of being lost in the desert. Or it might be referenced as something an elderly person might be hospitalised for – after working in the Garden too long.
In parts of Europe, it even has something of a mythical status – The Slavic legendary figure of Poludnitsa, or the Noon Witch, is the personification of heat stroke – striking down people working in the fields.
But what is heat stroke? How easy is it to get, and how dangerous is it? And are there good ways to avoid getting it?
What is heat stroke?
Heat stroke is a severe medical condition resulting from a person’s body temperature getting too high – generally around or above 40°C. Heat stroke can have a variety of causes, with two of the most common being exertion (exercise) and high-temperature environments – or possibly both.
Heat stroke is life-threatening and generally requires urgent treatment. If not treated promptly, victims can suffer organ damage, fall unconscious, or even experience organ failure.
Difference between heat stroke and heat exhaustion
You may have heard the terms heat stroke and heat exhaustion used interchangeably at times, but this isn’t accurate. In reality, heat exhaustion refers more generally to the body’s response to overheating. Heat stroke is effectively an extreme form of heat exhaustion, but it actually has different symptoms – showing that the overheating is beginning to become dangerous and life-threatening.
Heat exhaustion involves a lot of things that we commonly associate with severe overheating – such as sweating, headaches, dizziness and feeling nauseous. Exhaustion and weakness are also common (hence the name of the condition) – which in the case of heat exhaustion caused by exercise can often be taken just for general over-exertion or tiredness. The person might also experience muscle cramps, and their pulse rate might be weak but rapid. They might also have fast, noisy breathing. And although it seems a little odd for a problem caused by overheating, it’s not unusual for the person to have cold, clammy skin at first – later becoming flushed and red. If the person’s temperature is measured somehow, it will be above the human average of 37°C.
Heat stroke has some of the same symptoms, but there are important differences which can signal that the condition is becoming dangerous. The person may still experience nausea and headaches, although these might be more serious than before – the headache might now have a throbbing sensation. They might still be taking rapid, noisy breaths. They will also likely be red and flushed. But they might show the following key differences to someone with heat exhaustion.
- Dry skin / no sweat – Once a person begins to move into actual heat stroke, they may actually stop sweating. This can sometimes be taken as an indication that their condition is improving, but it’s actually a sign that the mechanisms the body uses to control its temperature are starting to fail. Although victims suffering from heat stroke caused by physical exertion will often still sweat.
- Disorientation or irrational behaviour – People can behave oddly or seem unusually disoriented as the condition begins to affect their brains.
- A rapid, strong pulse rate – The pulse will continue to be rapid, but might become stronger. This is a sign of the body desperately pumping blood around the body to regulate temperature.
- Loss of consciousness – Eventually, the person may loose consciousness as parts of their brain start to overheat.
If measured, the person will have a body temperature well above 37°C, and possibly even above 40°C (which is in the life-threatening range).
Why heat stroke occurs
Your body actually needs to maintain a very specific internal temperature to function – around 37°C (give or take a few decimals). A few degrees too hot or cold, and you can be in real danger. Usually, your body has a range of mechanisms that is uses to regulate temperature – including sweating (cooling you down by causing evaporation on the skin), rapid breathing, and blood flow – and stay in the suitable temperature range.
Heat stroke happens when something prevents your body from cooling itself down. This might be because a person has been exerting themselves (heating you up faster than your body can cool itself down again), because the weather is unusually hot, because you’re wearing hot clothing, or due to medical complications. It’s not unusual for several of these factors to come into play at once – such as firefighters running into burning buildings with heavy protective gear.
One common cause of heat stroke is children or animals left in hot cars. Without air conditioning or proper ventilation, the temperature of a car in the sun can go up very quickly – the windows and the metal body can act a little like a greenhouse. An animal or a small child can’t let themselves out of the car to find relief and might not even be able to signal their distress to others – meaning heat stroke is a real risk. This is one of many reasons why leaving a child in a car unattended is a criminal offence in many states.
When your body reaches dangerously high temperatures, some of its mechanisms to regulate temperature can start to fail – meaning things can go from bad to worse very quickly. At this point, as things progress, you can begin to suffer long term organ damage, organ failure, brain damage, and death.
First aid for heat stroke
If you believe someone to be suffering heat stroke, you should call 000 for an ambulance as soon as possible – it’s a life-threatening condition, and the longer the person goes without treatment, the more risk they’re at of permanent organ damage or death.
If you’re caring for someone who’s suffering from heat stroke, the goal is to get their body temperature down – fast. Your first port of call is a cool, shady spot, removing any unnecessary clothing as soon as possible.
The “Gold Standard” treatment for heat stroke is to immerse them in ice water – a bathful of water with a couple of bags of ice in it (perhaps from the esky) is a good option. This is not dissimilar to what a hospital might do. The person should be monitored at all times to make sure they don’t lose consciousness and slip underwater. Ordinary cold water is another option, although less effective. A cool shower might be helpful as the flowing water can rapidly conduct heat out of the body (like running a burned hand under a tap), but the person may need assistance to make sure they don’t pass out and fall in the shower.
If an ice bath isn’t an option, another decent option is water sprayed over the body with a steady flow of air over the person – perhaps from a fan. This allows the water to evaporate, taking the heat with it. This can be combined with cold compresses. You shouldn’t try wrapping the person in wet towels or clothing, as (after a short period of cooling) this can trap in the heat.
It’s also essential to help the person rehydrate, as their body might be dehydrated and unable to cool itself properly. Water can help, although if your body lacks electrolytes, it might struggle to absorb water – meaning sports drinks such as Gatorade or solutions such as Gastrolyte or Hydralyte can help. Avoid more than a litre of water every hour, as too much water can be harmful if your body is struggling to absorb it.
Where possible, getting help from someone with first aid training is valuable. In addition to knowing how to respond to various medical issues (including hyperthermia and heat stroke), they have practical skills like CPR in case the person’s condition deteriorates. If heat stroke or other head-related illnesses or injuries are a real risk in your home or workplace, it’s worth considering getting first aid training yourself!
If you suspect someone has been suffering from heat stroke, they should be assessed by a medical professional. Preferably this would be by an ambulance paramedic or at the nearest ED.
How do I avoid heat stroke?
Much of the process of avoiding heat stroke is reasonably commonsense. Some of the key methods are:
- Stay Cool – It seems obvious, but keep an eye on the weather and the temperature of the area you’re in. Make sure you’re not spending too long in direct sunlight, and you’re taking breaks to cool down.
- Wear suitable clothing – In hot weather, wear light, breathable clothing. If outside, make sure you have a good hat to keep the sun off. If, for some reason, you need to wear warmer clothing (such as if you’re working with bees, for example), make sure to take regular breaks and get out of the hot gear.
- Have a plan to cool down – Think ahead, and know what steps you need to take to cool down – whether that’s going inside and turning on the air conditioner or just grabbing a cool drink in the shade.
- Stay hydrated – Make sure your body has what it needs to stay cool by drinking plenty of water.
- Limit hot activities – If you’re doing a very hot task, consider if it can wait until a cooler time of day – or a cooler day overall. If not, limit the amount of time you’re doing hot work and take frequent breaks to cool off.
- Watch out for others – Keep an eye on others to make sure nobody’s overdoing it. Remember that children and the elderly are particularly at risk from heat stroke.
- Never leave children or animals in a car – If you’re out of the car for more than a minute or two, your kids and pets shouldn’t be left in the car alone – especially in hot weather. You can literally kill them. Don’t become one of those cautionary tales.