It's finally winter!

(Source: Network)
In winter, you will always see a group of "chasing the light" girls, they love the "little sun", are keen on warm babies, can't do without hot water bottles, love electric blankets, they are——
Girl with cold hands and feet!
(Source: First Painter of National Costume Zhimei)
For the reasons for the cold hands and feet, there are many opinions, some say that there is a lack of exercise, some say that the body fat is too low, and some people say that this is a manifestation of poor health.
(Source: A blind date program)
So, exactly, are these true?
You may not believe it, but the cold hands and feet in winter are actually a kind of protection for us by the body.
We have blood vessels all over our bodies, like underfloor heating, supplying nutrients and heat, maintaining life and body temperature.
In the skin, there is a group of "scouts", cold and temperature receptors, which can participate in adjusting the surface temperature as the outside temperature changes.
When they perceive a drop in ambient temperature, they trigger the constriction of the peripheral blood vessels of the skin, reducing the flow of blood to the surface of the skin, and "limiting heating" to the skin [1].
Allow more blood to flow to the heart and lungs to keep the body's core organs warm [1].
Since the hands and feet are the ends of the cycle, it is natural to feel cold.
In girls, this effect of contracting blood vessels in the limbs is more obvious, so it is usually easier to have cold hands and feet than boys.
In addition, the "big thermogenic household" in girls - usually has less muscle than boys, and the thermogenic capacity is lower.
The body fat content of partial girls is generally higher, and although fat can keep important internal organs warm, it will also make it more difficult for the heat in the body to reach the skin.
These factors add up to create a situation where girls are prone to cold hands and feet.
Although cold hands and feet are a normal physiological phenomenon, if the cold is accompanied by the following 3 conditions, it must be paid attention to, it may be that the body is signaling to us:
1. Raynaud's syndrome
In addition to cold hands and feet, if the fingers/toes are first pale in case of cold, followed by purple, flushing, accompanied by itching, tingling or burning symptoms, be careful of Raynaud's syndrome.
This is a vascular dysfunction disorder that may also be secondary to some connective tissue diseases (eg, systemic lupus erythematosus, dermatomyositis, etc.[2]).
In addition to cold stimulation, emotional agitation and mental tension can also be induced.
2. Arterial occlusion of the lower extremities
If the cold in the lower limbs gradually worsens, there is also a long walking time with weakness in the lower limbs (usually behind the lower legs), soreness and pain, and even skin darkening and ulceration, be careful of lower extremity arterial occlusion.
This is a disease caused by vascular lesions.
In simple terms, the arterial blood vessels of the lower limbs "harden", "thicken" and "narrow" become like aging water pipes, resulting in insufficient blood supply at the distal site and causing a series of limb ischemia symptoms.
People who smoke, are obese and have "three highs" (high blood pressure, high blood sugar, and high blood lipids) should pay more attention.
3. Hypothyroidism
In addition to being afraid of cold, you always feel tired, sleepy, or feel memory loss, there are menstrual irregularities, bloating and constipation, lower limb puffiness and other manifestations, be careful of hypothyroidism.
The disease is an endocrine disease caused by insufficient secretion of thyroid hormones, and laboratory tests can find a decrease in thyroid hormones (T3, T4) and an increase in thyroid-stimulating hormone (TSH).
If there is no above problem, try the following methods, it is generally enough to keep warm!
1. Direct heating
The most direct method: hot water bottle, warm baby, electric blanket, etc.
They are all warmed up by heat conduction, but special attention needs to be paid to their use:
Hot water bottle to choose electric wire type hot water bottle (heating pipe feels like a U-shaped tube or semi-circular), the traditional electrode type hot water bottle is cheap, but there is a risk of explosion;
(Source: Help Video)
Do not hold for a long time, do not use overnight, otherwise it is easy to burn;
Avoid direct contact with the skin and warm it up with clothing or blankets.
2. Exercise
Muscle contraction during exercise produces heat energy, which, coupled with increased heart rate and faster blood circulation, can transfer heat to the peripheral limbs.
Studies have also shown that exercise can convert white adipose tissue in the body into brown fat capable of producing heat [3].
In addition, exercise can also strengthen and enlarge the muscles of the body, helping to keep out the cold!
3. Soak your feet
The principle of soaking feet to warm up is actually very simple, on the one hand, it is the transfer of heat, on the other hand, the peripheral blood vessels of the feet feel the rise in the external temperature and cause relaxation, which brings the heat in the body to the skin.
However, this method is not suitable for people with varicose veins in the lower limbs and occlusion of the arteries of the lower limbs, and it is easy to aggravate the disease.
Friends with diabetes are slow because of the peripheral sensory nerve endings, it is easy to judge the water temperature inaccurately, resulting in burns and infections, or try to avoid it.
Healthy people, especially older people, are not recommended to soak every day, even if soaking feet, not more than 15 minutes, because doing so for a long time may lead to a decrease in vasodilatory capacity.
4. Keep the key parts warm
Protect the head, neck, knee joints, ankles and other parts, and the whole person will be much warmer.
(Source: Shenzhen Weather)
Be careful to avoid wearing tight clothes and shoes, which can affect peripheral blood circulation.
5. Find a boyfriend
Of course, there is also a cost-effective and efficient "killer" - find a boyfriend with a constant temperature, put cold little hands and little feet on his stomach...
Finally, I wish all the sisters a boyfriend to warm their hands this winter
Reviewer
Zhang Tianhua | Deputy Chief Physician and Associate Professor of Vascular Surgery, Second Affiliated Hospital of Harbin Medical University
bibliography
[1] Lalonde S, Beaulac K, Crowe TG and Schwean-Lardner K. The effects of simulated transportation conditions on the core body and extremity temperature, blood physiology, and behavior of white-strain layer pullets. Poultry science. 2021;100:697-706.
[2] Casanegra AI and Shepherd RF. Raynaud Phenomenon and Other Vasospastic Disorders. Cardiology clinics. 2021;39:583-599.
[3] Lu Wang, Li Fu, Exercise Promotes Browning of White Fat, Chinese Journal of Sports Medicine, 2020, 39(6): 486-490
*The content of this article is a popularization of health knowledge and cannot be used as a specific diagnosis and treatment recommendation, nor is it a substitute for face-to-face consultation by a practicing physician, for reference only.
*The copyright of this article belongs to Tencent Medical Code, unauthorized media reprinting is prohibited, and illegal reprinting will be investigated for legal responsibility according to law. Individuals are welcome to forward to the circle of friends.
* Welcome to WeChat search and pay attention to the public account "Tencent Medical Code" to get more health science knowledge.