Cold sensitivity or cold intolerance is unusual discomfort felt by some people when in a cool environment.

There is much variation in the sensitivity to cold experienced by different people, with some putting on many layers of clothing while others in the same environment feel comfortable in one layer.

Cold sensitivity may be a symptom of hypothyroidism

Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...

, anemia

Anemia

Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

, fibromyalgia or vasoconstriction

Vasoconstriction

Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...

 (according to article Sauna

Sauna

A sauna is a small room or house designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these and auxiliary facilities....

). There may also be differences in people in the expression of uncoupling protein

Uncoupling protein

An uncoupling protein is a mitochondrial inner membrane protein that can dissipate the proton gradient before it can be used to provide the energy for oxidative phosphorylation.There are five types known in mammals:* UCP1, also known as thermogenin* UCP2...

s, thus affecting their amount of thermogenesis

Thermogenesis

Thermogenesis is the process of heat production in organisms. It occurs mostly in warm-blooded animals, but a few species of thermogenic plants exist.-Types:...

.

It has been found that one's state of mind influences one's perception of ambient temperature. Thinking about an incident where one felt excluded caused experimental subjects to estimate the ambient temperature 3 degrees Celsius lower than subjects who thought about experiences in which they felt included.