Feeling cold all the time is common, but it’s not something you should simply accept as a quirk. While some people naturally run cooler than others, persistent cold intolerance often points to an identifiable cause, from an underactive thyroid to low iron levels to simply not eating enough calories. The key is whether your cold sensitivity is new, worsening, or paired with other symptoms.
Your “Normal” Temperature Is Lower Than You Think
The old 98.6°F standard is outdated. A Stanford Medicine analysis of more than 618,000 temperature readings found that the average adult body temperature today hovers around 97.9°F, with a normal range of roughly 97.3°F to 98.2°F. Body temperature also fluctuates throughout the day, dipping lowest in the early morning and peaking in the late afternoon. So if you feel chillier at certain times of day, that’s completely expected.
What matters more than a single number is your personal baseline. If you’ve always been the person reaching for a sweater, that may just be your physiology. But if feeling cold is a recent change, or it’s getting worse over time, something metabolic or circulatory is likely shifting.
Why Women Feel Colder Than Men
If you’re a woman who’s constantly cold while the men around you seem fine, biology is working against you. A study in the Journal of Applied Physiology found that men’s resting metabolic rate is about 23% higher than women’s, largely because men carry more muscle mass. Muscle generates heat even at rest, so more muscle means a warmer body.
Women also lose heat faster. Because women tend to have a higher surface area relative to their total body volume, heat escapes more quickly through the skin. The result: less heat produced, more heat lost. To make things worse, most office thermostats were calibrated using a model from the 1960s based entirely on male metabolic rates, potentially overestimating female comfort needs by up to 35%. If your workplace feels freezing, the building’s climate system may literally not be designed for your body.
Thyroid Problems and Cold Sensitivity
Your thyroid gland acts as the master regulator of your metabolism, and metabolism is the engine that generates body heat. The thyroid produces two hormones that tell your cells to burn fuel and stay warm. When the gland doesn’t make enough of these hormones, a condition called hypothyroidism, your body slows down to conserve energy. Your internal thermostat drops, and cold intolerance becomes one of the most noticeable symptoms.
Hypothyroidism affects roughly 5% of the U.S. population and is far more common in women, especially after age 60. Beyond feeling cold, look for fatigue that doesn’t improve with sleep, unexplained weight gain, dry skin, thinning hair, and constipation. A simple blood test measuring thyroid hormone levels can confirm or rule it out, and treatment is straightforward once diagnosed.
Low Iron and Anemia
Iron-deficiency anemia is one of the most overlooked reasons people feel cold. When your iron is low, your body can’t make enough hemoglobin, the protein in red blood cells that carries oxygen. Less oxygen reaching your tissues means your body loses the ability to mount its two main defenses against cold: tightening blood vessels near the skin to conserve heat, and ramping up your metabolic rate to generate more warmth. Both of these processes need oxygen to work properly.
Anemia is diagnosed when hemoglobin drops below 13.5 g/dL in men or below 12.0 g/dL in women. Other signs include unusual fatigue, pale skin, brittle nails, and shortness of breath during activities that used to feel easy. Heavy periods, a diet low in red meat or leafy greens, and frequent blood donation are common contributors.
Circulation Problems Worth Knowing About
Raynaud’s Phenomenon
If your fingers or toes turn white or blue in response to cold or stress, then flush red as blood flow returns, you may have Raynaud’s phenomenon. During an episode, small blood vessels in the extremities spasm and temporarily shut down circulation. The affected area feels cold, numb, and may tingle or throb as it warms back up. Triggers can be surprisingly minor: grabbing something from the freezer or walking into an air-conditioned building on a warm day. Raynaud’s is more common in women and people living in colder climates.
Peripheral Artery Disease
Peripheral artery disease (PAD) happens when fatty deposits called plaque build up inside your arteries, narrowing them and reducing blood flow to your limbs. One foot or leg feeling noticeably colder than the other is a hallmark sign. Other symptoms include cramping in the calves, thighs, or hips when walking or climbing stairs (which stops when you rest), leg numbness, and slow-healing wounds on the feet. PAD is more common in people over 50, smokers, and those with diabetes or high blood pressure. Unlike Raynaud’s, PAD involves structural changes to your blood vessels and carries serious cardiovascular risk.
Not Eating Enough Can Make You Cold
Your body converts food into chemical energy, and a significant portion of that energy is released as heat. When calorie intake drops, your body compensates by dialing down energy expenditure, a process called adaptive thermogenesis. In practical terms, your internal furnace turns down to match your reduced fuel supply. This is why people on very restrictive diets, or those with eating disorders like anorexia, often report feeling cold to the bone. It’s not just about having less body fat for insulation. The body is actively producing less heat to stretch its limited energy stores further.
Even moderate undereating over weeks can trigger this response. If you’ve recently cut calories significantly and notice you’re colder than usual, your body is telling you it doesn’t have enough fuel.
Other Conditions That Cause Cold Intolerance
Diabetes can contribute to feeling cold through two pathways: nerve damage in the extremities that distorts temperature sensation, and kidney or circulation problems that reduce blood flow. People with diabetes who notice increasing cold sensitivity in their hands or feet should mention it at their next visit, as it can signal worsening nerve involvement.
Dehydration is another subtle contributor. Water makes up a large portion of your blood volume, and when you’re dehydrated, circulation to your extremities slows. Chronic mild dehydration is surprisingly common, especially in older adults whose thirst signals become less reliable.
Low body weight, regardless of the cause, reduces the insulation your body has and limits the amount of muscle tissue available to generate heat. This is true whether the low weight comes from illness, genetics, or intentional restriction.
Signs Your Cold Sensitivity Needs Attention
Feeling chilly in an air-conditioned room is one thing. The following patterns suggest something worth investigating:
- New onset: You used to tolerate cold fine, but now you can’t.
- Asymmetry: One hand or foot is consistently colder than the other, which can signal a circulation problem.
- Color changes: Fingers or toes turning white, blue, or deep red.
- Accompanying symptoms: Fatigue, unexplained weight gain or loss, hair thinning, dry skin, or leg cramps when walking.
- Numbness or tingling: Especially in the hands and feet, which may indicate nerve involvement.
A basic workup for persistent cold intolerance typically involves blood tests checking thyroid function, hemoglobin and iron levels, and blood sugar. These are inexpensive, widely available, and can quickly identify the most common culprits. If the results are normal and your cold sensitivity is longstanding and stable, you’re likely just someone who runs cool, and layering up is the most effective treatment available.