Health problems to be aware of in the mountains

Looking at images of people climbing Mt. Fuji on social media, everyone seems to have a happy smile, giving the impression that it's an easy mountain to climb. However, we must not forget that it is a high mountain exceeding 3,000 meters and "the highest mountain in Japan." Let's make sure we understand the physical ailments that are particularly common when climbing Mt. Fuji.

altitude sickness

Hypothermia

heatstroke

Exhaustion-related disaster

Altitude sickness

One of the most common reasons why climbers have to abandon their ascent of Mt. Fuji is altitude sickness. To enjoy a safe and comfortable climb, let's take precautions against altitude sickness.

Altitude sickness is a condition that develops when the oxygen level in the blood decreases.
If you continue climbing like this, your symptoms will worsen.
Lack of sleep or poor physical condition can easily worsen the condition.

Headache, dizziness, feeling of lightheadedness
Fatigue, feeling of weakness
Loss of appetite, nausea, vomiting, etc.
It can also lead to life-threatening complications such as cerebral edema and pulmonary edema.

Preventive measures

Holding back urination or restricting fluid intake can slow down your metabolism, making you more susceptible to altitude sickness. Therefore, be sure to drink fluids frequently.
It's not recommended to collapse into sleep as soon as you arrive at the mountain hut. When you sleep, your breathing becomes shallow, and if your breathing is shallow before you've acclimatized to the altitude, you're more susceptible to altitude sickness. When you arrive at the mountain hut, spend about an hour unpacking your belongings or enjoying the scenery to allow your body to adjust to the altitude, and then get a good night's sleep.
Children have weaker cardiopulmonary systems, and especially on their first climb of Mt. Fuji, they may not get enough sleep, putting them at a greater risk of altitude sickness than adults. Please pay close attention to your child's condition and never push them too hard.

Before departure, take a break of about 1 to 2 hours at an altitude near the 5th station to acclimatize to the altitude.
Walk at a slow, steady pace.
Take a deep breath, exhaling fully from your stomach.
Stay hydrated by drinking fluids frequently (sports drinks are more effective than plain water).
Take short breaks regularly, just enough to keep your body from getting too cold.

Having one pulse oximeter per group to measure blood oxygen levels and regularly recording and managing each member's blood oxygen levels during the climb makes it easier to detect signs of altitude sickness. Generally, a reading below 90% indicates signs of altitude sickness, and a reading below 80% is dangerous (you should descend immediately).

Countermeasures for altitude sickness

First, stop climbing for a moment and rest your body while consciously taking deep breaths.
When climbing in a group, people tend to try too hard not to inconvenience others, and their own reactions can become slower, so it's important to communicate with each other.
Descending is the best course of action. In most cases, you will recover naturally by descending and increasing your oxygen intake. The mountain is not going anywhere. Don't insist on reaching the summit; prioritize getting home safely.

If symptoms are severe, descend the mountain.
Keep your body warm and rest.
If your condition worsens, go to the First-Aid Center.

<Quick Note>
I sometimes see hikers in the mountains who, during breaks, hold commercially available canned oxygen bottles close to their bodies and continuously inhale it.
While it's true that breathing becomes easier while you're using it, you'll never have enough oxygen canisters, and the moment you stop using them, the oxygen level returns to that of that altitude, making you even more susceptible to altitude sickness.

The important thing is to allow your body to adapt to the oxygen level at that altitude. Use canned oxygen only temporarily when you are really struggling, and don't rely on it too much. Try to acclimatize to the altitude by taking deep breaths. If you can't let go of the canned oxygen and can't climb without it, you should stop climbing and descend immediately.

Symptoms of hypothermia

You might think that hypothermia is unthinkable in the middle of summer, but the time spent waiting for the sunrise on the summit of Mt. Fuji is the coldest time of day, with temperatures in the single digits even in mid-summer, and it's not uncommon for them to drop below freezing in early July or from late August onwards. Let's understand hypothermia correctly and take precautions.

Hypothermia refers to a condition in which the temperature of vital organs such as the brain and heart (core body temperature) is below 35°C. It is classified as mild if the temperature is between 32-35°C, moderate if between 28-32°C, and severe if between 20-28°C.
Hypothermia can occur even in the middle of summer or at low altitudes if you are exposed to wind for a long time while wet from rain or sweat, causing your body temperature to drop. If your autonomic nervous system is disrupted due to stress or other factors and the vasoconstriction function does not work properly, the balance with heat dissipation is lost, making you more susceptible to hypothermia.

Full-body tremors, chills, drowsiness, unsteady gait
↓
Loss of consciousness, tremors stop, inability to stand.
↓
Coma, cardiac arrest

While the above might give the impression that the condition progresses gradually over a long period, in mountain environments, loss of consciousness occurs rapidly. The frightening thing is that once you first feel chills and shivering, the progression is very quick.

Preventive measures

1) Keep your body warm and dry.

Wear quick-drying underwear.
Wear something warm, like fleece.
Rainwear provides windproof and waterproof protection.

2) Consume high-calorie foods frequently.

Chocolate and nuts
A warm, sweet drink

Countermeasures for hypothermia

1) Take shelter in a warm place that is protected from the rain and wind.

nearby mountain hut
(However, please absolutely refrain from occupying or locking yourself in toilets or mountain hut storage rooms, as this will cause trouble for others.)

2) Warm the body from the inside and out.

Change wet clothes
Hot drinks
An emergency blanket can be useful in an emergency.
(However, be sure to collect it after use so that it does not become waste.)

Generally, the temperature drops by 0.6°C for every 100m increase in altitude. Also, the perceived temperature drops by 1.0°C for every 1m/s increase in wind speed, so even if it's summer at the base of a mountain, it can feel as cold as early winter at the summit.

Temperatures can drop depending on the weather and time of day, so dress in layers to help regulate your body temperature.

Symptoms of heatstroke

While altitude sickness and hypothermia tend to be the main concerns when climbing Mt. Fuji, there is also a risk of heatstroke. In particular, the trails of Mt. Fuji offer very little shade from trees, meaning you often climb with direct sunlight on the back of your head, so caution is necessary.

Dizziness, lightheadedness, excessive sweating, muscle cramps
↓

Headache, nausea, fatigue, decreased concentration and judgment
↓

Impaired consciousness, seizures/convulsions, high body temperature, inability to walk straight.

Preventive measures

Wear a wide-brimmed hat that also covers the back of your head.
(It's easily blown away by the wind, so fasten the chin strap.)

Wear cool clothing.
(Especially during the descent, some people suffer from heatstroke because they haven't adjusted their clothing after being overdressed at the summit and haven't drunk enough water.)

Remove your mask as needed when outdoors.

Stay hydrated by drinking fluids frequently (sports drinks and oral rehydration solutions are effective).
(A guideline is 1.2L per day. Especially when taking the Yoshida, Subashiri, and Gotemba Trails, be sure to secure enough water for the descending trail.)

Heatstroke prevention measures

Check if the person is conscious. If not, request rescue.
Seek refuge in a cool place, loosen your clothes, and let your body cool down.
(If you have a wet towel or a cold plastic bottle, apply it to areas where arteries pass, such as the neck, armpits, and groin, to effectively lower your core body temperature.)

If the patient can take in fluids on their own, replenish fluids and electrolytes.
(Forcing someone to drink water while they are unconscious is not recommended.)

If symptoms still do not improve → Request for assistance

Fatigue

Unlike altitude sickness or hypothermia, fatigue simply means you're too tired to walk. In a city, even if you're too tired to walk, you can take a bus or taxi home, or you can rest in a coffee shop and still get home even if it's late at night. But what about in the mountains?

There are no buses, taxis, or cafes in the mountains. No matter how difficult it is, you have to descend the mountain on your own to get home.

When you can no longer descend the mountain on your own, that's when you're in trouble.DistressIt is.

The graph above shows the breakdown of mountaineering accidents during the climbing season in Shizuoka Prefecture. Accidents due to fatigue, which accounted for 14% of 2021, increased by 30% to 22 cases (44%) the following year. As will be discussed later, Yamanashi Prefecture does not count accidents due to fatigue due to differences in its transportation system, but the number of inquiries related to fatigue also increased similarly.

Since 2022 was a time when entry restrictions from overseas due to the COVID-19 pandemic were still in place, there are concerns that the trend of increased fatigue-related accidents will become even more pronounced from 2023 onwards, when entry restrictions are expected to be lifted.

<Let's learn about the evacuation system in case of an emergency.>

When a climbing accident occurs on Mt. Fuji during the summer climbing season, the response differs between Yamanashi Prefecture and Shizuoka Prefecture.

In Yamanashi Prefecture, on the Yoshida Trail, the 5th station General Administration Center, operated by the prefecture, serves as the command center for information gathering and other functions. A "rescue association," organized around mountain huts, works in cooperation with mountain huts, fire departments, and other organizations to transport injured or ill individuals down to the 5th station using crawler vehicles (transport vehicles), where they are then loaded into ambulances for transport.

In the case of Shizuoka Prefecture... due to differences in the number of injured and ill people, Shizuoka does not have the same transportation system as Yamanashi, and transportation is basically done manually by the police.

<Crawlers are not taxis!>

The photo on the right shows a transport vehicle called a crawler, which is used to transport supplies to mountain huts and also plays an active role in emergency transports by the "Rescue Association" on the Yoshida Trail, as mentioned earlier. Emergency transports by crawler are privately operated and therefore incur a fee. Also, "emergency transport requiring a crawler" means "transportation to a hospital by ambulance is required," so arrival at the 5th station means handover to an ambulance. There are occasional cases of trouble, so please be sure to understand this beforehand.
While calling ambulances instead of taxis has become a social problem, operating crawler vehicles involves various costs, and the number of vehicles and drivers is limited. Therefore, we must allocate our vehicles to more serious cases involving life-threatening situations. Crawler vehicles are not taxis. They are not something you can hop on casually just because you're tired, nor are they something you can simply use by paying a fee. We ask for your understanding.

Preventive measures

1) Build up your physical strength!

Strengthen your legs and core by hiking in nearby mountains.
Endurance training

2) A mountain climbing plan that is appropriate for your current physical condition and allows for some leeway.

Don't be overconfident based on outdated perceptions (especially for middle-aged and older people).
We plan to arrive at the mountain hut before sunset.
Especially for those who are hiking on a day trip using the bus, it's important to do thorough research beforehand to find out what time you need to start descending (whether you reach the summit or not) to avoid missing the last bus back.

For emergencies requiring rescue, please click here.

Emergency Contact Information