Heat Stroke Hazard
Our body temperature is generally maintained at around 37°C. A build-up of excessive body heat can lead to serious consequences. Overheating the body can cause serious impact to the brain - generally known as "heat stroke". Heat stroke victims must be treated without delay. The most basic rule is to help the victim dissipate body heat. Heat stroke can cause death within a very short time, so treatment must be speedy.
Overheating results from extreme or prolonged exposure to heat. As the body tries to rapidly dissipate the excessive heat, the blood vessels near the skin surface expand. This results in the blood supply to the brain and other vital organs running low, and so the victim looses consciousness. Early signs of overheat are dizziness and palpitations, followed by nausea, vomiting, headache, restlessness and finally unconsciousness. The obvious symptoms are cold sweaty skin and abnormally low body temperature.
Heat stroke is caused by poor sweating and heat dissipation. When we work in extreme heat for an extended period, the function of our sweat glands will slow down or even stop. This prevents proper heat dissipation. At the onset of heat stroke, the victim feels very hot. This uneasiness is quickly followed by an unclear mind, disorientation and finally unconsciousness. Obvious signs are a high body temperature exceeding 40°C and very warm skin with no sweat.
Guidelines for Replenishing Salt
It is a common belief that periodic intake of salt can make up the loss caused by exercising in hot weather. The truth is, our normal diet contains sufficient salt to restore a healthy level. Unless you are in high temperature continuously for three or more days, there is no need to take any salt supplement. As pure salt absorbs water, it is not advisable to take salt tablets. To avoid stomachache, drink warm water with salt instead.
Precautions for Exercising in Hot Weather
We lose a considerable amount of moisture when we engage in outdoor activities in hot weather. It is crucial to replenish water and salt. There is a common misconception that drinking too much water will reduce the level of salt and minerals. The truth is quite the contrary. Drinking water is a good way to replenish body moisture and minerals.
Dehydration can cause heat stroke or collapse. It is important to stay in the shade and take breaks regularly. Avoid doing strenuous exercise at mid-day or during the early hours of the afternoon.
People with heart disease, diabetes or fever are more prone to heat stroke and collapse. For them extra care is advised.
Cold distress or "hypothermia" often occurs when the hiker is not adequately protected by thermal clothing. It can also be a combined effect of hunger and cold. The victim will feel chilly, reflexes become slow, and other symptoms like haziness, grumpiness, abnormal behaviour, wobbliness, convulsion and shivers soon set in. To prevent cold distress, wear good thermal clothing and protect yourself with extra clothes when you stop to rest. Eat nutritious food along the way to ward off hunger.
Help the victim to a sheltered spot away from any wind. Protect him/her with extra clothing (but not too much) and lie him/her down in a sleeping bag. Make a hot drink for the victim (don't give any food or drink if unconscious). Never apply direct heat such as a hot water bottle), for this will cause blood pressure and body temperature to drop drastically as blood vessels sudden expand.
Getting Lost in Thick Mist or Heavy Rain
In spring, thick mists are common in Hong Kong's countryside. On a bad day, visibility can be down to a few feet. Hiking in this kind of weather calls for extra care. Before entering an area with thick mist, make sure you know your exact position, and note the local environment and scenic features to help identify your present location. If the area you are in suddenly becomes misty, stay calm. Try to find a return path. If your fellow hikers are tired or you are uncertain about the return path, the safest thing is to stay put in a nearby sheltered place and wait for help.
Make sure all members of the group stay close together. Above all, never allow anyone to wander off. Don't finish your emergency food in one go. Divide it up to make it last longer. Send out an SOS phone call right away. In the spring and summer months, thunderstorms are com- mon in Hong Kong. Thunderstorms often come with torrential rain and it poses considerable danger to hikers. There have been fatal accidents from lightning strikes on Lantau Peak, Tai Mong Tsai and Lamma.
Lightning usually strikes the land at abrupt high peaks or exposed ridges. The great electric current does not stop at the contact point, but is conducted to the ground for a further distance before finally dying out. Hikers are more likely to be hit by the ground current than struck by the actual lightning.
When the Hong Kong Observatory issues a thunderstorm warning, or when you see rain clouds gathering, stay away from peaks and high ridges. Don't make your way downhill along a spur, and don't stand near trees, telephone posts, lampposts, HV cable posts or high towers. Never take cover in shallow ditches or among rocks. If there are village houses nearby, seek temporary shelter there immediately. If it's too late to move, find somewhere safe near a small mount of seven to ten metres. Keep your hands off the ground, put your feet together, and kneel on an insulated object or gravel. Never sit or lie on the ground. Try to keep your body dry.
It is best to spread the group to several nearby locations. That way, if hikers in one position are struck, there will be others to give first aid.
Hong Kong has almost no rivers, but there are many streams and watercourses in our countryside. Heavy rain can turn trickling streams into raging torrents. Never underestimate the force of these fast and devastating torrents. A rushing waterway the depth of your ankles is powerful enough to throw you off your feet, while knee-deep water can wash away water buffaloes and other large animals. Never hike along a river valley, stream or basin, and don't wade across streams, catchwaters or dams. Following heavy rain, steep or weathered slopes are potentially hazardous. To avoid the danger of landslides, finds a safer route. If there is a landslide, stay calm. Seek shelter in a safe place high up, and hold on to a tree or large boulder. Never run in panic or act alone.