'Cold hands warm heart, why women often have colder hands than men' is a short video that uses infrared imagery to demonstrate the difference in heat radiation between a woman's and a man's hand. You surely recognize this scenario: You are lying in bed, all comfy and relaxed, and without any warning at all your lovely partner beside you pushes her icy hands (or feet) unexpectedly against your warm body. The next second your heart is about to stop. Your horrified brain thinks it is suddenly in the middle of an Antarctic winter and your neighbor is now wondering what the origin is of that spinechilling shriek that came through the wall...
Why is it that lots of women have colder hands and feet than men? The difference is thought to be due to a combination of factors, including differences in body composition, circulation, and hormone levels. While it's important to remember that not all women have cold hands and not all men have warm hands, this difference is a common phenomenon experienced by many.

MORE SCIENCE ABOUT COLD HANDS:

Science hasn't it all figured out yet, but this is what we know so far: The old saying "cold hands, warm heart" may go a long way to explaining why women's hands are colder than men's. The University of Utah researchers used thermal images to compare the hands of men and women and found that women's hands typically run 2.8 degrees Fahrenheit or 1,6 degrees Celsius colder than men's. It's still a bit of a mystery why, but scientists suggest that differences in body size, composition, metabolism and hormones are the culprits.
ABOUT EXPOSURE TO COLD exposure to the cold causes blood vessels in the hands and feet to contract, reducing blood flow there as the body seeks to protect the heart and other vital organs. While this happens in men and women, the cold response is much quicker for women.
ABOUT SURFACE AREA / HAND & BODY SIZE (VOLUME) Women tend to lose heat more quickly since they have a higher surface area compared to the total volume of their bodies. The same is true with your hands, which also have a large surface area‐to‐volume ratio (hands have a lot of skin but not a lot of mass). So it’s no coincidence that one of the first signs of being cold are cold hands.
MUSCLE MASS AND FAT Men tend to have a greater muscle mass than women which helps them to generate heat. The extra fat women generally have protects the vital organs, including the uterus, but it also restricts blood flow to the extremities. While body fat does provide some insulation, it isn’t nearly as good at keeping us warm as muscle tissue.
ABOUT METABOLISM Women produce less heat than men due to slower metabolic rates, so they tend to feel colder more quickly when temperatures drop. A study in the Journal of Applied Physiology showed that the resting metabolic rate, or the amount of energy your body burns at rest, was 23% higher in men than women.
ABOUT HORMONES Estrogen can lower women’s body temperature, cause heat to dissipate and slow blood flow to the hands and feet, making them more sensitive to cold.
ABOUT A MEDICAL CONDITION For most women, having cold hands isn't cause for concern unless it is a symptom of a medical condition known as Raynaud's. A person with Raynaud’s disease experiences pain in the extremities when temperatures drop. Blood vessels narrow and almost completely shut down. Fingers or toes turn from white to blue and, then, as the blood returns, they flush red. Apart from cold, stress can cause these symptoms too. Women are five to nine times more likely than men to have Raynaud's. There are two types of Raynaud's primary and secondary. The secondary type is caused by an underlying condition and is less common. The primary type is linked to family history. Raynaud’s disease affects 5 to 10 percent of Americans. There is no cure for Raynaud’s disease, but there are ways to manage the symptoms. The National Heart, Lung, and Blood Institute (NHLBI) suggests wrapping up and keeping the house warm when temperatures are cold, as far as possible avoiding emotional stress, exercising to promote a healthy lifestyle and reduce stress, avoiding medicines and substances that trigger the symptoms, limiting consumption of caffeine and alcohol, not smoking. They also suggest following up with a physician, especially if sores develop on the extremities. Getting medical help may prevent a worsening of symptoms and serious complications. Apart from Raynaud's disease, there are other underlying medical conditions why you might feel cold all the time, such as diabetes, hypothyroidism and anemia.

Sources:

https://www.engineeringtoolbox.com/te...
https://medicalxpress.com/news/20171...
https://www.medicalnewstoday.com/arti...
https://www.mcgill.ca/oss/article/hea...
https://onlinelibrary.wiley.com/doi/a...
https://www.womansworld.com/posts/hea...