The severity of cold temperatures goes beyond what a thermometer can measure. This was evident during the recent winter in India where nearly 900 people succumbed to hypothermia, even though the temperature did not drop below 5 C. Human warmth is constantly produced, making it difficult for us to gauge our susceptibility to cold based on a thermometer reading. We lose heat to the environment regularly to maintain our core temperatures at 37 C. The faster we lose heat, the colder we feel. Wind chill plays a significant role in this. Our body heat produces a thick layer of warm air that is stripped away by the wind, causing rapid heat loss. The colder the temperature, the more effective the wind is at reducing body warmth.
Measuring the perception of cold rather than the actual cold is challenging. Wind chill tables, created in the 1940s, rely on data involving plastic containers with water freezing in different temperatures. Recent attempts have used surface thermometers to measure skin temperature, helping adjust wind chill levels differently for various human behaviours like travelling on a motorcycle or skiing. Conduction is another major player in the way we feel cold, with a room feeling chilly at 2 C and a lake at that temperature causing death within minutes. Wet clothing is also worse than no clothing, losing heat twenty times faster than dry clothes.
Hypothermia has three phases: the first phase is marked by violent shivering and confusion, with the victim being conscious but unable to take coherent action. The second phase leads to a general lowering of metabolism, loss of consciousness, muscular rigidity, and fluttering of the heart muscles. The third phase, below 24 C, results in the body losing its ability to regulate temperature, culminating in death. Mental effects can be very dangerous, leading to confusion, loss of coordination, and slowing of reaction time that can cause fatal accidents. The recent cold spell in India affected many homeless individuals as they lacked the necessary warm clothing and blankets, making them more vulnerable to hypothermia.
Internal defences become weaker when external defences like shelter or clothing are absent. These defences can be further weakened by malnutrition, as seen in a 1971 study in Uganda, where mild temperatures rarely dropped below 16 C, but people still succumbed to hypothermia. In-flight hypothermia can also occur in operating theatres due to the effects of anaesthesia and strong air conditioning. Overall, experiencing the effects of cold temperatures is not just about the reading on a thermometer.
Long-term protein deficiency in children has been linked to hypothermia. In a study conducted in Kampala, 20 out of 24 patients studied died of hypothermia or related conditions. The report’s authors concluded that malnutrition was the primary cause of death, rather than environmental cold.
Hypothermia is a serious danger, and weakened individuals are particularly vulnerable. It can occur in any climate, from tropical to sub-arctic regions. However, those most at risk are individuals without financial means to protect themselves.
Lack of access to proper clothing, heating, or shelter can lead to a higher risk of hypothermia. This vulnerability is often seen in populations with limited financial resources. Hence, financial stability can play a vital role in reducing the risks of such conditions.
