The fastest way to warm up when you’re cold is to get moving, layer up, and eat something. Your body has powerful built-in heating systems, and most of the techniques that work best simply help those systems do their job. Whether you’ve just come inside from freezing weather or you’re sitting at a desk that never seems warm enough, here’s what actually raises your body temperature and what just feels like it does.
How Your Body Generates Heat
The moment your core temperature starts to drop, your brain triggers a chain reaction. Blood vessels near your skin constrict, pulling warm blood away from the surface and toward your vital organs. Your adrenal glands release stress hormones that crank up your metabolic rate. And if you keep getting colder, your muscles start contracting involuntarily: shivering. Shivering is remarkably effective at producing heat, though it’s uncomfortable and burns through energy fast.
Understanding this helps explain why some warming strategies work better than others. Anything that boosts your metabolic rate or reduces heat loss from your skin will warm you up. Anything that only warms one small patch of skin gives you a sensation of warmth without doing much for your core temperature.
Move Your Body
Physical activity is the single most effective way to generate heat quickly. Even light movement like walking, doing jumping jacks, or climbing stairs forces your muscles to burn fuel, and a byproduct of that combustion is heat. You don’t need an intense workout. A few minutes of brisk movement can raise your skin temperature noticeably, and sustained activity keeps it elevated.
If you can’t get up and move around, try tensing and relaxing major muscle groups in your legs, core, and arms. This mimics what shivering does naturally but puts you in control. Clenching and unclenching your fists or bouncing your legs under a desk generates enough muscular activity to take the edge off.
Layer Clothing Strategically
Clothing doesn’t generate heat. It traps the heat your body is already producing. That’s why layering works so well: each layer creates a pocket of still air that acts as insulation. Thermal scientists measure insulation in units called “clo.” A summer outfit provides about 0.6 clo, while a full ski outfit hits around 2 clo. For serious cold, polar gear reaches 3 to 4 clo. You can roughly add up the insulation value of each layer to get the total.
The most important principle is keeping the layer closest to your skin dry. Cotton absorbs moisture and holds it against you, which accelerates heat loss. Wool and synthetic fabrics wick moisture away and continue to insulate even when damp. If you’re choosing between a cotton hoodie and a wool sweater, the wool will keep you meaningfully warmer. Beyond that, covering your head, neck, and hands matters disproportionately because those areas have high blood flow near the skin’s surface and lose heat quickly.
Eat Something, Especially Protein
Digesting food generates heat. This is called the thermic effect of food, and it varies dramatically by what you eat. Protein produces the most heat: your body burns 20 to 30 percent of the calories in protein just to digest it, releasing that energy as warmth. Carbohydrates produce a moderate amount (5 to 10 percent), while fat generates very little (0 to 3 percent).
In practical terms, eating a high-protein meal or snack (eggs, chicken, cheese, nuts, yogurt) will warm you more from the inside than a buttery pastry or a bag of chips. One study found that two hours after eating, a protein-rich meal generated roughly twice the internal heat of a carbohydrate-heavy one and nearly three times that of a fatty meal. If you’re chronically cold at your desk, a protein-rich lunch may genuinely help.
Warm Drinks: Comfort, Not Core Heat
A hot cup of tea or coffee feels warming, and that feeling is real, but it’s mostly sensory. By the time a hot liquid reaches your stomach, it has already cooled significantly. As one physician at UVA Health puts it, there’s “hardly any warmth left” by that point to meaningfully raise your core temperature or widen blood vessels.
That said, warm drinks still have value. They warm your hands through the mug, they soothe your throat, and the comfort factor is genuine. A caffeinated drink also gives your metabolism a small nudge. Just don’t rely on tea alone if you’re truly cold. Pair it with food, movement, or better insulation.
Take a Warm Bath or Shower
Immersing yourself in warm water transfers heat to your body far more efficiently than warm air does, because water conducts heat about 25 times faster. The key is getting the temperature right. Research on rewarming shows that water between 37 and 39°C (about 99 to 102°F) is the safe and effective range. That’s roughly body temperature or just slightly above, which feels comfortably warm but not hot.
Avoid water that’s too hot. Studies on frostbite rewarming found that water at 45°C (113°F) actually caused tissue damage rather than helping. Even if you’re not dealing with frostbite, very hot water after cold exposure can cause a sudden drop in blood pressure as your blood vessels rapidly dilate. Warm, not scalding, is the rule.
If a bath isn’t an option, a warm shower works well. Even running warm water over your wrists and hands for a minute can help, since those areas have blood vessels close to the surface that carry warmth back to your core.
Adjust Your Indoor Environment
If you’re cold indoors, temperature isn’t the only factor. Humidity plays a surprising role in how warm you feel. At the same air temperature, higher humidity makes your body feel warmer. Research testing people at 26°C found that raising relative humidity from 30 to 60 percent increased both skin temperature and the sensation of warmth. In winter, indoor air often drops well below 30 percent humidity because heating systems dry it out. Running a humidifier can make a room feel warmer without touching the thermostat.
Drafts matter too. Moving air strips heat from your skin much faster than still air. Sealing gaps around windows and doors, or simply repositioning yourself away from a draft, can make a noticeable difference. A space heater aimed at your feet warms the part of your body most likely to feel cold first, since your circulatory system deprioritizes your extremities when conserving heat.
Use Direct Heat Sources Safely
Heating pads, hot water bottles, and electric blankets transfer heat directly to your body and work well for localized warming. Place them against your torso rather than your hands or feet. Your core is where warming matters most, and blood flowing through your warmed torso will carry that heat to your extremities naturally.
One caution: if your skin is numb from cold, you may not feel a burn developing. Check the temperature of any heating device against the inside of your forearm (where sensation is more reliable) before pressing it against cold skin. Wrapping a hot water bottle in a towel provides a buffer.
When Cold Becomes a Medical Concern
Normal cold discomfort is one thing. Hypothermia is another. Mild hypothermia begins when your core temperature drops below 35°C (95°F), and the warning signs include intense shivering, slurred speech, confusion, clumsiness, and drowsiness. If someone shows these symptoms after cold exposure, the recommended approach is passive rewarming: dry clothes, blankets, a warm room, warm drinks if they’re alert enough to swallow. The safe rewarming rate is gradual, roughly 0.5 to 2°C per hour.
People who are chronically cold without obvious environmental reasons may have an underlying issue. Low thyroid function, anemia, poor circulation, low body weight, and certain medications can all reduce your body’s ability to generate or retain heat. If you’re always the coldest person in the room despite eating well and dressing warmly, that pattern is worth investigating.