Fri | Jun 22, 2018

The dangers of cold weather

Published:Tuesday | December 24, 2013 | 12:00 AM

It appears that we are in for a cold winter season, and changing weather conditions create increased stress on the human body. The very young, the elderly, and people with conditions like heart disease, diabetes, and circulatory problems have greater health risks in cold weather. This is of relevance even in the Tropics, where the temperature can fall suddenly at night.

Even the use of certain drugs like alcohol and sedatives can increase a person's risk of cold weather-related illness because they interfere with the body's heat-regulation system. People who work in cold environments are at risk of hypothermia, the medical term for an abnormally low body temperature. Even if you are walking or exercising outdoors in the cold, you must be aware of the danger of hypothermia.


The early signs of hypothermia are referred to as the 'umbles' - when an individual mumbles, stumbles, fumbles, and grumbles. Anyone who is shivering, not thinking straight, has slurred speech, or has trouble holding on to an object with his hand should be put into a warm environment immediately, and if the symptoms fail to improve quickly, a doctor should be consulted.

More colds and flu

Every year, adults in the developed Western world get an average of three colds per year, and about 20 per cent of them get the flu. Although colds and flu are not confined to cold-weather months, they are much more prevalent at that time. One reason researchers give is that the influenza virus likes cold, dry air. Scientists at Mount Sinai School of Medicine in New York City found that low humidity provided the ideal conditions for the influenza virus to survive whereas high humidity is fatal to this germ. They also found that animals transmit the influenza virus to each other better at low rather than at high temperatures.

Another study in Wales suggests that cold temperatures can promote a cold by reducing the number of infection-fighting white blood cells in the nasal passage, where cold viruses most often enter the body.


About five per cent of people, three-quarters of them women, experience seasonal affective disorder (SAD) each year. This is a type of depression that typically occurs during the cold-weather months. This may be related to a reduction in the production of the hormone melatonin by the brain when the hours of sunlight are reduced.

Some symptoms of SAD are similar to those of other types of depression: sadness, low energy, excessive sleepiness, social withdrawal, and poor concentration. However, people with SAD are more likely to move very slowly, crave carbohydrates, and gain weight, and are less likely than people with conventional depression to have feelings of worthlessness or thoughts of suicide.

Heart Attacks and Hypertension

Numerous factors like obesity and cigarette smoking can increase your risk of heart attacks, but interestingly, heart attacks are more common in cold weather. Researchers in the United Kingdom found that there is a two per cent increase in heart attack risk for 1° Celsius drop in the average daily temperature. This may be because cold spells increase blood pressure and put more strain on the heart. Also, the heart has to work harder to maintain normal body temperature when the ambient temperature is low.


According to research published in the journal Frontiers in Bioscience, because winter can worsen high blood pressure, it can trigger strokes. Experts point out that temperature shifts from warm to cold can cause your blood vessels to constrict and precipitate a stroke. Aneurysms in the brain, which are bulging blood vessels with weakened walls, are more prone to rupture and result in a stroke when the temperature falls.

High cholesterol

Cholesterol levels are highest in the winter and lowest in the summer. Researchers in the journal Archives of Internal Medicine reported that 22 per cent more people had high cholesterol in the winter months than in the summer months. The researchers concluded that this difference in cholesterol levels might possibly be due to people exercising less in the cold months, but I suspect it may be a reflection of lower vitamin D levels in winter.

Skin problems

Some skin diseases are aggravated in the winter months when dry air, decreased sunlight, and colder temperatures contribute to dehydrated skin, with decreased blood flow. For example, psoriasis, a disorder that produces scaly skin, often worsens in cold weather.

The Vitamin D connection

It is extremely interesting to note that all the problems listed above are aggravated by low vitamin D levels. In my opinion, the reduced exposure to sunshine during the winter months, with a resultant lowering of vitamin D levels, constitutes a major causative factor. Sadly, mainstream medicine continues to turn a blind eye to the extreme importance of vitamin D for optimal health. The current recommended daily intake of vitamin D is woefully low, and during the winter season, I suggest taking at least 5,000 units daily.

Keeping healthy in the cold

It is important to keep warm and dry. Dress appropriately and invest in basic items like umbrellas and sweaters.

Hydrate and humidify

Cold weather can mask the sense of thirst and thus discourage adequate fluid intake. Do not wait until you feel thirsty. Drink lots of fluids, especially water, warm herbal teas, soups, and protein-rich shakes, but be careful with alcohol as this dehydrates and increases heat loss. If possible, use a humidifier in the home and office during cold spells.

Eat right

Avoid the carbohydrate cravings that the cold induces and focus on protein-rich foods, complex carbohydrates, and healthy fats.

Strengthen your Immune system

Supplement with antioxidants like vitamins A, C, E, minerals like selenium and zinc, and herbs like Echinacea, schizandra, rosemary, ginger, and garlic. Get enough sleep, and when available, get lots of sunshine.

Exercise sensibly

Keep active but do not overexert yourself in cold weather. Warm up first and keep well hydrated before, during, and after exercise.

You may email Dr Tony Vendryes at or listen to 'An Ounce of Prevention' on POWER 106FM on Fridays at 8 p.m. His new book 'An Ounce of Prevention, Especially for Women' is available locally and on the Internet.