What happens when your body no longer reacts or reacts inappropriately to temperature changes? This is a reality for many people with an SCI
Most of us have a body temperature that runs at about 37ºC. When it is hot, our bodies react to help us cool down and we nudge it along by dressing in cool clothes. When it is cold, our bodies react to warm us up and we help by dressing warmly. This is a normal, everyday part of living.
But for individuals with a spinal cord injury (SCI) that affects the neck or upper chest, things are very different: their bodies can no longer react or they react inappropriately to the temperature within the environments by keeping them colder than they care for or hotter than they are comfortable with.
The inability of the body to react to the environment by cooling down or warming up can have very dangerous consequences – and even cause death! Because individuals with high-level SCIs are unable to help themselves, it is essential that caregivers understand what is happening and how to assist.
But first, let’s look at some physiology: how normal bodies work and what goes wrong in individuals with high-level SCIs.
Humans and animals have been able to survive, live and thrive in extreme weather conditions from Arctic ice to tropical heat. How do we do this? Temperature regulation is a balance between heat generation and dissipation. Our body heat is generated in our deep organs and in the contraction of skeletal muscles.
Heat is lost mainly through the skin, but also by breathing, which is why dogs pant in hot weather. People also tend to breathe faster when they are hot. The skin regulates body temperature in a number of ways, including through blood vessels under the skin that dilate in hot weather so that heat radiates out through the skin. In cold weather, the same blood vessels contract and direct blood away from the skin, to conserve heat.
The skin also has sweat glands that open in hot weather and push out lots of sweat to cool us down. When it is cold, we sweat less and our hair follicles become erect so that our body hairs stand up and conserve heat by insulating the skin – we get goose-bumps. Our muscles also help to warm us in cold weather by shivering. This produces energy that warms us.
All these temperature-regulating methods are controlled by a centre in the brain called the hypothalamus, whose function is to maintain the body’s temperature at 37ºC. It does so by receiving information from temperature sensors under the skin and in deeper organs.
Based on the information received from these sensors, the hypothalamus instructs the endocrine system to produce more or less energy (heat), whichever is required, and the autonomic nervous system to regulate blood vessels by contraction or dilation, sweating and shivering, as needed.
The hypothalamus also sends messages to the brain to makes us aware when we are too hot or cold. With high SCIs, the normal connections between the hypothalamus and the temperature sensors are lost. There is loss of awareness below the level of the injury regarding temperature. The outflow messages from the sympathetic nerves to the blood vessels, sweat glands and muscles are broken.
Thus, there is a loss of blood vessel constriction or dilatation. The body can no longer conserve or deliberately lose heat in response to temperature change. As the person with the SCI loses the ability to shiver, the body also loses some of its ability to produce heat. Sweating is also ineffective below the level of injury.
In effect, the brain does not get temperature-related information from the environment or body and it also can’t tell the body what to do. The brain is isolated. In a nutshell, persons with high SCIs have, to a greater or lesser degree, lost their ability to differentiate between hot and cold as well as the ability to compensate for too hot or too cold conditions.
To aggravate this, some persons with SCI – particularly those associated with traumatic brain injury – may also have a body temperature set at higher or lower than 37ºC, which drives them to want to compensate for this. This feeling may be continuous or may be triggered by an event that causes discomfort.
The role of the caregiver
You as a caregiver must know the person for whom you are caring. The person may feel hotter or colder than you do in a given situation. For example, don’t insist on a jersey just because you put one on yourself. Here are some particulars of temperature regulation to consider.
Dress the person warmly and take particular care of the hands, feet and head. Consider gloves, warm socks, scarves and cosy headgear. Dressing in three to four layers takes time and effort initially, but often works better than a single, very thick garment. It’s also easier to adjust to the temperature (by removing layers) as the day warms up.
The main challenges of protecting against cold happen at night, when the person is asleep. Exposure to cold can cause various complications, including Autonomic Dysreflexia (which I shall describe in a future article). Dress the person in layers such as a vest, T-shirt, bedclothes and even bed socks.
After each turning, place the person in the foetal position with legs up against the trunk. This helps to conserve heat. However, when doing so, be aware of clonus or jerks, as these are indications that the body is experiencing discomfort. In this case, reposition the body until the limbs relax.
Check pressure points to protect against pressure sores. Lastly, cover the person in a way that does not allow cold air to sneak in and settle between the shoulder blades or the legs.
Hot conditions and post-exertion
Overheating can cause a heat stroke and even death. Apart from the obvious precautions of cool clothing, protective headgear, lots of fluids and avoiding the sun, other aids include mist-water sprays that mimic sweating, ice water and even ice cubes, which can be sucked to help cooling down from the inside.
A wet cloth (especially from a freezer) on the head or back of the neck does wonders. Most importantly, in hot weather or cold, use your initiative. Make use of what is available. You and the person you care for are a team. Understand what works and what doesn’t and figure out the best ways to solve tricky situations together.
Ida’s Corner is a regular column by George Louw, who qualified as a medical doctor, but, due to a progressing spastic paralysis, he chose a career in health administration. The column is named after Ida Hlongwa, who worked as caregiver for Ari Seirlis for 20 years. Her charm, smile, commitment, quality care and sacrifice set the bar incredibly high for the caregiving fraternity.