Heat Stroke: How Not To Turn Holidays Into a Nightmare 

Heat Stroke: How Not To Turn Holidays Into a Nightmare 

An early heat wave that hit Greece last June has claimed five lives, including the famous British journalist Michael Mosley, and with another three people missing the death toll may rise. Sadly, it is not the first time that tourists have lost their lives due to hyperthermia, one of the most tragic being the death of Violet Gigano back in 2021 — the 29-year-old nurse from France who succumbed to a heat stroke in Crete, ten minutes from her car on the E4 trail connecting Krios to Elafonisi beach. Not more than a month later, another British hiker, also in Crete, suffered the same fate.  

All these people were on holiday, walking or hiking under the scorching summer sun without a worry in their minds, so the big question is: Were their deaths preventable? Sadly, these people could potentially have been saved, had they known more about heat fatigue, its symptoms, and the importance of not letting the situation escalate to a heat stroke which is a life-threatening condition, especially for children and people over 60.  

The human body is a fine-tuned machine that can seamlessly maintain its temperature at around 36.5°C (97.7 F). If this sensitive balance gets disrupted, things can go south pretty fast. Hyperthermia is the rise of core body temperature beyond normal levels caused by high ambient temperatures and intense body activity rather than fever. It comes in many shapes and forms, often starting as heat exhaustion, a condition characterized by excessive sweating, fast breathing, tiredness, nausea, high body temperature, rapid heart rate, and thirst.  

The problem is that most of these symptoms are common with those of high-level activity, including elevated core body temperature which you usually can’t tell anyway. To get an idea, the human body produces 15 to 18 times more heat during a marathon. This heat production can raise body temperature by 1°C every 5 minutes. When the body is unable to sustain its core temperature within a normal threshold (thermoregulate itself) then heat exhaustion kicks in. If left untreated, it can escalate to heatstroke — a way more serious and potentially lethal condition with symptoms like confusion, seizure, even higher body temperatures (>40°C, 104°F), and eventually loss of consciousness.   

The biggest threat to hikers is exertional heatstroke (EHS), which is caused by intense body activity, in conjunction with higher outside temperatures (usually over 23-24°C — 73-74°F). Unlike the classic heatstroke, which is characterized by the lack of sweat, in EHS sweating may still be present. Eventually, the symptoms can escalate with the addition of other potential side effects including rhabdomyolysis (the body breaks down the muscles), leaky gut (increased intestinal permeability), and lactic acidosis (high levels of lactic acid in the blood). Finally, the organs start to suffer and even a septic shock may occur. Heat strokes can leave permanent damage to people who have survived one.  

female hiker under a tree, hiding from the sun

Experiencing Hyperthermia  

I have suffered from heat exhaustion twice, and in one of those situations, I more than likely stepped into heat stroke territory. The first time was on a long hike in High Tatras (Priecne loop), Slovakia. It was a bit hot, but not terribly; bear in mind that I live in Cyprus so I’m acclimatized to 40°c (104°F) plus temperatures. I was carrying my usual 12kg backpack, but I was not used to high elevation gains back then. That day, the temperature was around 24°C (75°F), but the sun was scorching the valley. Back then, I was in great condition, having run a half marathon in two hours sharp no more than 6 months ago (I was by no means a seasoned long-distance runner though).  

When we had set that morning, the weather had been quite chilly and I kept my windbreaker on for far too long, making my first mistake. Two and a half hours into the hike, I started to feel bad — tired, overly sweating, fast heart and breathing rate, my quadriceps pumped and heavy. But, with a few breaks I managed to push through. Halfway into the hike, while I was on a via Ferrata, and even though I was feeling a little better after a lunch break, persistent heat cramps struck me on both quads while I was scrambling my way up the steep and quite exposed slope, pinning me down.  

Fortunately, an old hiker from the queue I had created, was carrying electrolytes and magnesium tablets. After a thirty-minute rest on a tiny ledge, I was able to resume and reach Priecne Pass — the route’s highest point. Beyond that, the trail was mostly downhill, but I could feel my body being on the limit. Stupid mistake number two: I had a beer with my fellow hikers at a refuge.  

A good seven hours into the hike and fifteen minutes before the finishing point, we decided to visit some waterfalls no more than 10 minutes off the trail and around 50 vertical meters lower. When I started walking up the trail again, it struck me like thunder. My heart rate went crazy, I was gasping for breath, and each step felt like I was on top of Everest. I could walk only supported and unburdened. It took me more than half an hour to finish the 10-minute section to Hrebienok, and I almost collapsed in the funicular. The next morning, my heart rate was still 120 and the black color of my urine revealed what was probably the traces of rhabdomyolysis, my body literally dissolving my muscles. That was my closest call ever. An experience I will never forget, that has shaped my respect for mountains and toned down my ego ever since.  

The second time I suffered from heat exhaustion was six years later while hiking Enipeas Valley on my way to the top of Mt. Olympus in Greece. It was 37°C (99°F) and I was carrying a stupidly overweight backpack weighing more than 23kg. To make things worse, my hiking buddy and I, were walking along the river, so humidity levels were pretty high. I got the first symptoms three hours into the hike and even though I was drinking lots of water (perhaps too much), my condition didn’t seem to improve. My sweat had gone from salty (normal) to entirely watery and tasteless, which meant that my body had been washed off of precious salts and minerals.  

I was not only heat-exhausted, but I still had more than a day and a half of brutal ascent ahead of me. This time I played it safe. We decided to stop and camp one hour ahead of our schedule. I ate and got some good sleep, but the next day after hiking for an hour to the next waypoint, I understood that heat exhaustion was not behind me. I could feel that I had developed a sensitivity to heat stress. I would sweat and get tired more than usual, and in general, be more prone to the symptoms. With a heavy heart, I decided to take one more day off and strip at least 4-5 kilos from my backpack. Fortunately, that did the trick, and we eventually managed to step on the imposing Plateau of the Muses.  

My previous experience had surely helped me avoid the worst.  

In both cases, the single most important factor was that I was not alone. If hyperthermia can happen to seasoned hikers and professional athletes, then it can strike anyone. And, no, hiking along the coastline is not safer. Sometimes the Greek terrain is so barren that you cannot find a tree to rest under its shade for kilometers. Last but not least, some factors work against you from the get-go: Obesity, poor physical condition, having consumed even a small amount of alcohol, having a hungover from the previous day, having spent the previous days outside in high temperatures, being on antihistamines or other medication.  

How to Prepare for hot climates  

What to avoid  

  • Going out alone. That’s the most common mistake of people who died from hyperthermia.  
  • Walking during a hot day. A hot day for me may be different to what is a hot day for you. A 20km hike at 25°C is entirely different than at 35°C.  
  • Dress properly with light fabrics and cover your head. An umbrella might not be a bad idea either if you plan to spend some serious time outside.  
  • Leave a big margin for things to go wrong, like inaccurate forecasts, sickness, or even a broken bottle of water (it happened to me once).  
  • Let people know of your plans. Tell a friend or relative when and where you are going, so they can check on you by the end of the day.  
  • Start earlier. Try not to hike between 12:00 and 15:00. Having said that, during heatwaves, in countries like Greece you may encounter afternoon temperatures ranging way above thirty (86°F) and lots of humidity even after 6 pm.   
  • High humidity levels can make a huge difference and should always be taken into consideration since they prevent your body sweat from evaporating adequately to keep your temperature down.  


This is a complicated subject, and trying to acclimatize doesn’t come without shortcomings. According to studies, acclimatization in hot environments starts to take effect after a week and needs two weeks for aerobic performance optimization, which makes it impossible for short-term visitors to accomplish. To make things worse, the first days of experiencing a hot climate can actually cause accumulated fatigue and make you more sensitive to heat stress. If you are going on a summer hike, it may not be a bad idea to take the previous day off and stay in the shade.  


A study suggests that differences between different materials and cloth technology have a negligible effect on heat dissipation. So, sport company claims should always be taken with a pinch of salt. Thin fabrics, short sleeves, and short pants are optimal. Wear a breathable hat. Again, if you are walking on barren terrain for extensive periods, an umbrella may save your hide. Needless to say, you always need sunblock for the face and exposed skin.  


Just water. An extra bottle of electrolyte drink can help, and no, you don’t have to buy it. Many times, sports drinks don’t even contain enough sodium anyway. Put half a teaspoon of salt in a liter of water with a bit of honey and juice from half a lemon or orange. You’re welcome. To keep yourself hydrated, drink small amounts of water every 15 to 20 minutes. Don’t wait until you feel thirsty. If you do, it means you are already low on fluids. Don’t overdo it either.  You should just compensate for the fluids you are losing. Excessive water consumption may lead to hyponatremia — a low concentration of sodium in your blood, that leads to low energy, nausea, confusion, headache, and other nasty symptoms.  

I’m getting heat exhaustion symptoms, what now?  

  • Let your partner know, if you don’t have one, call someone, or tell fellow hikers, if there are any around. By the way, if you are hiking alone, you should at least have a PLB (personal locator beacon) device with you.  
  • Find a shade. Get under a tree, a big bush, or whatever can provide shade. I almost always carry a tarp that I can turn into a basic shelter with my trekking poles. It can make a difference between life and death.  
  • Hydrate, hydrate, hydrate.  
  • Have a snack to get back some electrolytes. Salty nuts are a good way to take sodium and some carbs to help you with energy. Electrolyte tablets can help but don’t rely heavily on them. They are no panacea on a hot day while carrying a huge pack.  
  • If you are near a body of water, get inside, if not, one of the most efficient ways to lower your temperature is spraying water on bare skin which lowers the temperature by evaporating and is much more efficient than just pouring water on yourself. So, having a small spray pump could be a valuable asset. Not to mention it needs way less water than other methods.  

Stay Safe

In conclusion, high temperatures are potentially dangerous and can put in danger anyone, at any time, and place. Especially, people who live in cooler climates should be extra careful, and tone down their activity level and pace significantly. The summer sun can be unforgiving and, for the most vulnerable, even a ten-minute walk to a bus station, or the closest beach could escalate into a serious situation with potentially health-threatening consequences. Enjoy the summer and always be safe. 


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Chrisostomos Kamberis
I'm a travel photographer and writer. Having worked in the tourism industry for years, I created Trip & Trail to share my love for
travel and photography with friends and anybody who has the same passion.


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  1. Katherine Banks on 6 July, 2024 at 02:59

    Such a great article!!

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