- 5 minutes to read
- 16 September 2019
How do we define sensitivity?
With sensitivity, we mean our fifth sense, namely feeling. Different from the other four senses, sensitivity is not perceived through a sensory organ such as vision is through the eyes. Our sensory system retrieves information from numerous nerve endings and receptors1 that are spread all over our body. This system gives us feedback from our body through pressure, stretching, vibration, temperature or pain. This feedback comes from different places: from the mucous membranes, the inner organs or the muscular / skeletal system (position of the joints, flexion of muscles).
This sensitivity is an important warning system of our body. If there is no or only partial sensitivity, we are not receiving information that would make us aware of hazards. Due to the limited sensitivity of people with spinal cord injury, this important warning mechanism is disabled, which can lead to various complications.
Risks due to limited or non-existent sensitivity
As a result of limited or non-existent sensitivity, the risk of pressure sores is particularly great for people with spinal cord injuries.
Burns through heat therapy and the touching of hot objects or surfaces
Heat therapy is one of the oldest medical treatments and is used in conventional Western medicine as well as in natural medicine. Since it is used in the home environment, nearly everybody knows it: it includes a number of different applications such as hot-water bottles, cherry pit pads, heating pads and blankets, red light therapy, warm compresses and heat packs. Usually heat applications are perceived as comfortable, relaxing and revitalizing. However, using heat applications can be dangerous if the perception of heat is limited because this can cause burnings and scalding.
Furthermore, there are many everyday situations in which we come into contact with hot objects and surfaces. If the person’s ability to sense the heat is eliminated or limited, one has to be especially careful with:
- Taking a shower or a bath (watch out for changing water temperatures!
- Sink drainage
- Heating pads or hot-water bottles
- Carrying hot objects on the legs (you need protection between the object and the legs, e.g. use a tray with equalising padding.)
- Surfaces that retain heat (deck chair, sand, etc.)
The perception of heat and cold is impaired when sensitivity is limited. This may lead to hyperthermia or hypothermia of the body. People with a high spinal cord injury often feel cold and therefore dress overly warm and enjoy the warmth of the sun.
However, the sun also has its drawbacks. UV radiation can damage the skin (sunburn), and heat can lead to an overheating of the body (sunstroke). Excessive sunbathing speeds up the ageing process of our skin and promotes several other skin changes – it may even cause skin cancer.
Check your skin for alterations after spending time outside. Good sun protection (hat, sunglasses and sunscreen) is recommended.
Regulation of body temperature
Humans regulate their body temperature by sweating, among other things. People usually start to sweat at air temperatures just over 30°C. People with spinal cord injury are only able to sweat as a regulating measure in those areas of the body that are not paralysed. This means that especially tetraplegics have a considerably limited ability to regulate their body temperature, which is insufficient to keep it within a normal range when they expose themselves to high temperatures.
Due to the spinal cord injury, the autonomous nervous system can no longer control the mechanisms responsible for our temperature regulation (heat production and heat loss). These mechanisms include blood circulation in the skin, sweating, shivering and directing the blood from the abdominal organs towards the muscles. This may result in a decrease in body temperature (hypothermia) or an excessive elevation (hyperthermia). These issues may be caused by high room temperatures, intense sun radiation or wrong clothing. People with tetraplegia therefore have to pay special attention to ambient temperatures. They need to be especially careful when travelling to very hot countries but also during the summer time in Switzerland.
The following points are important for tetraplegics but also for people with paraplegia:
Increased sweating requires increased fluid intake. As a general rule, the bladder should excrete at least 1.5 litres of urine per day. This helps to prevent thromboses and urinary tract infections.
The risk of thrombosis is increased during the hot season. Adequate fluid intake and compression stockings are the best possible prophylaxis. It is therefore important to check the legs for rashes, overheating, swelling and oedemas on a daily basis, because these are the first signs of thrombosis.
Sweating causes damp skin and thus increases the risk of pressure sores. Pressure relief in the wheelchair is therefore important in order to prevent pressure sores. Damp clothes need to be changed and the skin check should never be forgotten.
People who are taking anticholinergics such as Ditropan® (for the treatment of an overactive bladder) or Buscopan® (against stomach cramps and spastic constipation) only perspire to a limited extent and therefore need to be particularly careful when being exposed to the sun. It is also important to check the package information leaflet to see if taking these drugs increases photosensitivity.
What to do on hot summer days:
- Take along a spray bottle filled with water to spray on your body in the case of hyperthermia – this makes up for the limited perspiration.
- Always wear a hat
- Drink plenty of water
- Avoid heat
- Wear light clothing
- Use a mobile fan
Also hypothermia may have severe physical consequences and can even lead to unconsciousness. It is therefore very important to be especially careful when staying outside for a longer period of time, also during the winter time, for instance when going for a stroll or skiing.
What can I do when I notice that I am overheating?
Spraying yourself with cold water (e.g. with a spray bottle) may be very efficient. Also make sure you drink enough. In general you should avoid strong and direct sunlight.
Are electric heating pads better than hot-water bottles?
Electric heating pads can also become very hot and therefore you need to be very careful about where you use them. Generally, you should use them only in those areas that show sensitivity.
Is it still possible for people with tetraplegia to travel to countries with a hot climate?
Yes, if you follow the above-mentioned recommendations, it should be possible. However, not everyone can withstand heat equally well. If the heat causes blood pressure problems, isotonic drinks might help.
1 specialised cell that transmits stimuli