FIELD NOTES

Summer Hiking in Central Australia: Part 1: Environmental Conditions

Updated: May 16

The environmental conditions of Central Australia in summer is unlike anything most hikers have ever experienced on any previous hike (or in their lives). Not only is the failure rate very high, the risks posed to hikers is extreme, often resulting in near misses or serious injuries, illnesses and fatalities.





Article Context: The article was written with the multi-day, extended day and end-to-end (E2E) hiker in mind who is planning to hike the Larapinta Trail in summer. However, the article can apply to day walks or anything up to cross country treks across Central Australia during summer periods (October-March). This article is not a 'how to article' either. The intent of the article is to provide some basic information about the conditions out here in summer and some considerations to take into account. It has been written by LTTS staff who have had extensive experience in summer and extreme environment trekking in Central and Northern Australia.



IMPORTANT NOTE: Unless you are an experienced and competent* hiker who has had regular and extensive experience in long distance treks in rugged, hostile and extreme heat environments, it is strongly recommended you do not attempt such a hike in these conditions, especially alone.

INTRODUCTION


Some moderately experienced hikers who’ve hiked on the Larapinta Trail in summer had many near misses and endured hardships that they never expected or ever experienced before. Many hikers quit early or sustained injuries and/or needed evacuation or rescue. Some solo hikers suffered psychological impacts caused by overwhelming panic and despair, fear and terror, when they got lost, injured, fell ill and/or became delusional or disorientated.


The failure rate of medium to long distance treks in summer in Central Australia is approximately 98%.


Fatalities and serious injuries have occurred on just day walks in the West MacDonnell National Park. There have also been many near misses which could have had catastrophic consequences had it not been for vigilant Park Rangers and members of the public and the exceptional effort by the local emergency services and medical staff who carried out the rescues, evacuations and treatments.


By any standard a hike out here in summer is exceptionally difficult. A long distance trek such as an End to End in summer is perhaps one of the toughest hikes anyone could undertake. Undertaking such a hike in summer requires extensive preparation, training, knowledge, experience and a high level human performance capabilities.



Central Australia in Summer - An Overview


It is fair to say that unless you have lived in Central Australia (or in a similar region) and experienced a few summers here, it's likely you will not be able to comprehend what a desert or arid summer is like. Most people visiting here don’t. Experienced international hikers who trekked in North Africa and Central Asia during summer have said to us that their treks in Central Australia during summer was a lot more difficult and some of the hardest walks they have ever done. They described the intensity of the heat, low humidity and the sheer roughness of the terrain was incessant and an unrelenting assault on the mind, body and equipment.


Here is why.


Central Australia is an arid region, surrounded by vast deserts on all sides. The terrain around Alice Springs and the Larapinta Trail is mountainous and surrounded by flat or undulating and exposed rocky terrain. The ground and soil is hard and grainy with exposed rocky ground with embedded and loose rock - everywhere. The vegetation is sturdy and prominent but doesn't offer much serious shade or protection from the heat in summer. Unless you are in a cave, you cannot escape the hot air and wind even if you're in the shade. Even when in the shade, the wind (along with the extremely low humidity) is gradually dehydrating you - even if you're just sitting there and not moving.


In milder and balmy months, such as April or late August when temperatures sometimes level at around 31-33C during the day, many hikers express disbelief about how hot, windy and exposed they were on the trail. In the first couple of weeks in April 2018, an unseasonably warm month, there was a 74% failure rate with hikers on the Larapinta Trail. Now compare that to summer temperatures where the temps level out at around 40-45C (air temps). Combined with the ground or radiant heat, temps can be anywhere from 50-70C (due mostly to the baking exposed terrain (rock, hard soils, limited tree cover).


Add extreme UV exposure, hot and warm winds and low humidity levels, and what you get is an incredibly harsh, punishing and unforgiving natural environment or what could be called a 'hostile' environment - an environment that can and does kill. In these conditions, the human body's ability to regulate itself is greatly reduced or diminished.

Unless very carefully and strictly managed, dehydration is highly likely to set in and will be accompanied by the onset of heat related illnesses such as sunburn, dehydration and heat exhaustion. The looming onset of heat stroke, a potential killer, also becomes a serious and immediate threat. At about this time complications begin to surface with previous medical histories, illnesses and injuries. The most common being heart related conditions and previous injuries. Remember the human body is under great duress in these conditions. Weaknesses in the body from previous health issues are likely to become problems or issues which will require regular management.

If the hiker is alone and suffering from these hostile conditions or heat illnesses, there is a very high probability that panic and fear will slowly start to set in and gradually some very unreasonable or unrealistic decisions will be made due the altered mental states common with such conditions such as confusion, dizziness and eventual delirium. The often fatal decision to keep going is made and the hiker continues to keep walking, perhaps in overwhelming or uncontrolled panic and fear, in the scorching temperatures


High ground exposure: Full sun, limited or no shade, high winds. Note hiker in centre-right of image.

In these conditions with continual exposure and physical exertion in the extreme heat, much like what it would be like on the Larapinta Tail in summer, the body will quickly start to overheat. Once the core body exceeds 40.5C and continues to rise, the gradual and then eventual rapid shutdown of vital life support systems will begin. This starts damaging and shutting down the brain, heart, muscles and kidneys. Once the shutdown process begins, it is extremely difficult to slow down, reverse or even stop unless you receive immediate medical assistance ( i.e. multiple IV drips, rapid cooling ( i.e. ice baths etc) or immediate hospitalisation ( i.e ICU - Intensive Care Unit). Even then revival may not be possible and if it is, severe damage to vital organs has likely been caused, such as brain damage, some of which is irreparable.

Unfortunately for hikers walking alone in these types of hostile conditions and suffering from severe heat exhaustion or heatstroke, the outcome is often catastrophic. In many instances deceased hikers have been found with spare water, working mobile phones and even workable PLB's and SATPHONES. But it was too late for rational or clear thinking where even simple tasks are often very difficult. Deceased hikers have often been found sitting next to a shady cliff, cave or tree, perhaps a place where they needed to rest, but due to sheer heat exhaustion and shutdown, fell asleep and never woke.

A catastrophic tragedy.



There is limited 'effective' shade on the Larapinta Trail. Overall the trail is very exposed.

Five Key Environmental Factors in Summer


1. Temperatures

  • Summer in Central Australia is hot. Dry, baking and penetrating heat. Day temperatures average between 38-43C and in heatwave periods ( like now in Jan 2019), temperatures during the day have been regularly between 43-46C.

  • In this heat all your water, gear and equipment is baked hot. If you water is not insulated, you will drink very warm to hot water the whole time you are out here. Its one of the most enduring toils on the trail - drinking hot water when you are thirsty. (See Part 3 for tips to protect gear, food and water).

  • Ground temperatures are much hotter. This is called Radiant Heat. The radiant heat from the hot ground can often increase temperatures by 10-20C. Most of the terrain in Central Australia is directly exposed to sun so it would be sensible to assume if you are walking on the Larapinta Trail in summer expect radiant temperatures to be around 50-60C or more in some places. Enclosed Radiant Heat is when heat is trapped or concentrated in a natural enclosure such as a valley or a wide gorge where the walls of the gorge have been exposed to sun throughout the day. If there is no breeze in these enclosed area's, even if the breeze is warm or hot, the stifling heat can be unbearable to the point of despair.

  • Night temperatures during summer range between 24-33C, often cooling down closer to dawn such as 330am-430am ( just about the time you need to get up and starting your day!). It takes a long time for the ground to cool down so expect the radiant heat from the hot ground to remain that way for most of the night. If you plan to sleep on the ground you need very good insulation to stop the heat from the ground penetrating your mattress and your body. Most extreme heat trekkers have specialised air mattresses or use a hammock's.



Many parts of the trail has little or no shade. Image: Section 11

Expect 100% full exposure to the elements, with little relief, during summer treks. Image: Section 10


A good example of what an Enclosed Radiant Heat area would look like. Image: Section 5.

Any thickly vegetated and breezy shade or 'crown shades' are lifesavers. Image: Section 4

2. Humidity

Humidity during summer can range from 5-20%. Compare that to averages on the east coast which range from 50-70%. If you moisturise often back in Victoria, NSW or elsewhere because your skin feels dry, you will feel like sitting in a bathtub of moisturiser after a couple of days in Central Australia.

  • Many people visiting Central Australia have never experienced very low humidity. It catches a lot of people out completely by surprise. Dehydration is the first sign, but its so subtle here, that most people don’t recognise or realise it. On arrival to Central Australia, many visitors don't notice that the dehydration process has accelerated. This is particularity important for hikers when they arrive here before their trek. They need to increase their rehydration efforts two fold to avoid starting their trek dehydrated. (See Part 3: Trek Preparation)

  • When it rains or drizzles here even if its nearby 50km - 200km away the humidity levels increase substantially, but so can the sauna effect accelerating perspiration that can lead to dehydration a lot quicker.


3. Ultraviolet (UV) Index ( Solar Radiation)

  • The UV index during summer is Very High (8-10) to Extreme (11+) often increasing in intensity due to the high reflectiveness of the ground and rock surfaces of Central Australia. There is very little cloud cover in Central Australia, so often sun exposure if full and constant through the day. Even when there is cloud cover, UV is still a factor, though it does reduce its intensity.

  • UV is a radiation, so it will cause serious damage to the skin and eyes if not protected. Skin damage starts with sunburn which accelerates dehydration and other issues. UV penetrates clothing, but most clothing only reduces the amount of UV that reaches the skin and doesn’t entirely block it. Clothing does however reduce the levels of sunburn in summer but not entirely. Hikers will often apply sunscreen to the arms even if they are wearing shirts. Some hikers report 'radiation burns', burns which look like sunburn but had no exposure to the direct sun. The reflection of the UV from the rocky ground and hot winds would have been a key contributor.

  • Some clothing brands have UV protection and many professional and experienced summer trekkers wear only UV rated clothing.

  • LTTS staff use specialised clothing for summer treks which is made from a baseline combination of silk, cotton, hemp or bamboo (a tough, durable and comfy mix) and is constructed, stitched and treated to absorb UV light up to 50+ (UPF).

  • UV rays can also cause serious eye damage. The exposed conditions on the Larapinta Trail are often very bright and highly reflective, constantly bombarding the eyes (and whole body) with UV radiation at different angles throughout the day. Good quality sunglasses with a high UV protection rating is essential. LTTS staff regularly use high quality custom made Oakley goggles on extended treks in summer to protect the eyes from constant UV bombardment and heat reflection.


4. Wind

  • Wind on the trail is a big factor. The often hot or very warm breeze accelerates the dehydration process by sapping the moisture and sweat out of your skin, mouth, eyes and ears. The lack of any moisture on the skin (sweat) also reduces your body's ability to cool itself down, which is essential for body temperature regulation.

  • The LTTS team use sheamaghs (a type of Arabic headdress) to cover the neck, head, face, ears and mouth to reduce the radiant heat reaching the skin and reduce moisture extraction and rapid evaporation. Walking with your mouth open or exposed to dry hot air significantly increases dehydration.



Broken and highly reflective terrain with almost zero shade. Image: Section 8

Fully exposed high ground will deliver the full spectrum of impact. Image: Section 9

Open valley terrain will expose hikers to a hot wind tunnel. Section 9.

Rugged and exposed mountainous terrain. Not very shady. Image: Section 4.


5. Terrain


The terrain in Central Australia varies but its predominately flat or undulating lined with spectacular mountain ranges unlike anywhere else in Australia. Some of the peaks in these ranges like the Chewings Range and the West MacDonnell Ranges reach more than 1,000m above sea level.

  • There is one common feature across all of Central Australia though - its rocky. There are rocks everywhere. Big rocks, small rocks, boulders, pebbles and grains all of which are either loose, embedded, smooth or razor sharp . What this means is the ground is broken, rugged and hard to walk across and works to slow down everything in its path or break it down if it stays too long. The terrain causes many trips, slips and falls.

  • The terrain is an accelerator for dehydration, exposure and injury. Your body works a lot harder to negotiate such terrain. At the same time you are exerting more energy and your body is being exposed to extreme UV and radiant heat levels- a perfect combo that is gradually but surely grinding down the body and your gear. As your body gradually absorbs the impacts, it begins to weaken your system and one of the first things you start to notice is just how much more tricky the terrain starts to become now that your coordination is diminished by the effects of dehydration and fatigue.

  • The rocks are very reflective. The UV rays hit the ground in uniform rays and then get dispersed in all directions once it hits the broken ground blasting the body from every possible angle. So the hiker gets bombarded by UV from the top and the ground up.

  • The rocks substantially increase the radiant heat on the ground once the sun hits it and its rays bake it. Glues holding boots together have been known to melt or weaken, causing soles to slip off!

  • Here at LTTS we have special inserts in our boot soles for summer trekking that trap or deflect the heat from the ground and stop it going up the sole to the boots/feet. Our summer boots are customised for such conditions. We minimise the use of glues on our boots. Our boots are stitched with Kevlar stitching wherever possible. Any glue we do use is high grade military standard or MIL-SPEC.

  • Standard boots with no protection heat up incredibly causing all sorts of challenges to ones feet. It takes great care and regular treatment to protect feet from the siege of heat. ( Damaged feet and boots even in winter when walking is optimum here, is one of the single biggest issues challenging hikers).


The Larapinta Trail offers some of the most amazing scenery in Central Australia. Image: Section 8.

Another example of Enclosed Radiant Heat - A gorge. A natural oven. Image: Section 8.

The terrain around Hugh Gorge Trailhead.


Summary


The environmental conditions of the Larapinta Trail in summer are harsh and unforgiving. Very few people attempt any multi-day or extended treks in summer here. A handful of experienced trekkers have completed the trail E2E in summer with LTTS support but the trekkers did so at great expense, toil and through tenacious effort. Many of these trekkers are professionals or serious trekkers from Germany, South Africa, the US and Russia. Every single one of these LTTS customers planned and prepared for their trek over a 6-12 month period. As part of the trek preparation, they did trial treks in North Africa and in the deserts of Utah, Uzbekistan and other places. All these trekkers were still caught by surprise just how challenging the Central Australian conditions in summer were compared to other harsh areas around the world.


Plan carefully. Prepare competently. Upskill regularly. A trek out here in summer will most likely be one of the most arduous and punishing treks you will do in your life.



Next Articles in the Series - Coming Soon

  • Part 2: Physical Affects of the Environment: What to Expect

  • Part 3: Key Considerations for Planning and Preparation Before Your Hike

  • Part 4: Hiking in the Heat: Some Tips, Techniques and Practices.

  • Part 5: Post Trek. What To Do When You Get Back






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*A competent hiker is someone who extensively plans and prepares for their trek; they do the necessary courses and upskill; they are properly and adequately equipped; they have informed all the necessary people and organisations about their trek and have done so in detail; they carry the critical emergency communication devices (PLB's) and have comprehensive plans and procedures set out if something goes wrong


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Disclaimer: This article is for general information purposes only and is not meant as a recommendation. It is your responsibility to make sure you are properly informed, well prepared and capable of undertaking such a trek or activity. Read our disclaimer here


If you have any recommendations, suggestions or a correction you would like to highlight, email us at info@treksupport.com.au

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