The warm glow of a drink is misleading. Alcohol tends to cool your body down even while it makes you feel cozy, so chills during or after drinking are usually your body catching up to heat it has already lost. When the chills show up the next morning instead, they’re usually part of the hangover itself, not a sign you caught something. In people who drink heavily every day, though, shaking and chills after cutting back can mean something more serious.1PubMed Central. Alcohol withdrawal syndrome: mechanisms, manifestations, and management
How Alcohol Lowers Your Body Temperature
Alcohol widens the small blood vessels near your skin, sending more warm blood to the surface.2PubMed. Effects of ethanol on thermoregulation You feel flushed and warm, but that heat is leaving your body into the air. The temperature deep inside you can fall while you feel comfortable.3PubMed. Effects of ethanol on thermoregulation The more alcohol in your blood, the bigger the drop tends to be.4CrossRef / Journal of Wilderness Medicine. Alcohol ingestion and temperature regulation during cold exposure Smaller, leaner people lose heat faster and reach a higher blood alcohol level from the same drinks.
Your skin sensors read that warm blood as warmth, even as the inside of your body cools. That mismatch is why people skip a jacket or stay outside longer than they should.
Normally, when you get cold, you shiver, which makes heat by working your muscles. Alcohol’s most common effect in the cold is to dampen shivering, so you make less heat.5PubMed. Effects of ethanol on thermoregulation Part of the reason is that alcohol can drop blood sugar, which starves the shivering response of fuel.6Journal of Wilderness Medicine. Alcohol ingestion and temperature regulation during cold exposure In fact, low blood sugar can be a bigger reason drinkers get cold than the widened blood vessels.7Journal of Wilderness Medicine. Alcohol ingestion and temperature regulation during cold exposure
Drinking on an empty stomach makes the blood sugar part worse, while eating as you drink helps keep your shivering response working. Alcohol also seems to lower the temperature your brain treats as normal, so it stops defending against the drop.8Elsevier / PubMed Central. Effects of ethanol on thermoregulation
The chill often arrives late. Once you come indoors or the alcohol begins to wear off, skin vessels narrow again and warm blood stops pooling at the surface. The cold you weren’t feeling becomes obvious all at once.
Why You Get Chills During a Hangover
After an evening of binge drinking, resting heart rate the next morning runs higher, about 65 versus 58 beats per minute.9PubMed Central. Morning sympathetic activity after evening binge alcohol consumption The body’s stress response also reacts more strongly to effort the morning after.10PubMed Central. Morning sympathetic activity after evening binge alcohol consumption A pounding heart, sweats, and shakiness can come in waves along with the chills.
Your body also reacts as if mildly ill. During a hangover, levels of immune signaling chemicals rise compared with normal.11PubMed. Effects of alcohol hangover on cytokine production in healthy subjects That’s why it can feel like coming down with a bug, with chills, aches, and fatigue. Dehydration and swings in blood sugar make it harder to keep an even temperature on top of that.12Impact Recovery Center. How to Stop Alcohol Sweats: Causes & When to Get Help
You may wake damp with sweat from a restless night and feel chilled as it cools on your skin. Symptoms usually peak in the morning and ease through the day as the alcohol is cleared and you eat and drink. A measured fever is not a typical part of a plain hangover, so a real temperature reading should make you think of another cause.
Sleep adds to the problem. Body temperature naturally dips overnight, and alcohol deepens that dip while fragmenting your sleep. If you kick off the covers during a sweaty stretch, you can wake up chilled.
A few simple things help. Sip water or an electrolyte drink to replace the fluid you lost, in small amounts if your stomach is unsettled. Eat something with carbohydrates, such as toast or fruit, to lift the low blood sugar that is making temperature control harder. Warm up with dry clothes and blankets; a scalding shower can leave you lightheaded when you’re already dehydrated. Having another drink to feel better, the “hair of the dog,” only postpones the problem and brings back the heat loss.
When Drinking in the Cold Becomes Dangerous
A dangerous drop in body temperature is often reported in intoxicated people exposed to cold.13PubMed. Effects of ethanol on thermoregulation Alcohol makes people feel comfortable in the cold while their core temperature falls faster.14PubMed. Effects of ethanol on thermoregulation Colder conditions and leaner bodies make the effect stronger.15CrossRef / Journal of Wilderness Medicine. Alcohol ingestion and temperature regulation during cold exposure
Knowing the signs in a drinking friend can matter. Intense shivering that later stops is a bad sign rather than an improvement, because the body may be running out of ability to make heat. Confusion, slurred speech, and clumsiness look like drunkenness, so they’re easy to dismiss when they actually signal a falling body temperature. Very cold, pale skin or growing drowsiness means you should call emergency services without waiting. While help is coming, move the person indoors or out of the wind, remove wet clothing, and wrap them in dry blankets.
To stay safe outdoors, dress for the real temperature, not for how warm you feel. Eat beforehand and during to protect your blood sugar. Never let a drunk person walk home alone in cold weather, and don’t use alcohol to “warm up” after cold exposure. Warm, sweet drinks without alcohol help; alcohol only speeds heat loss in someone already cold.
Flushing and Racing Heart in Some Drinkers
Alcohol breaks down into a toxic byproduct. People with a common gene variant, frequent in East Asian ancestry, clear it slowly.16PubMed. The acute effects of ethanol and acetaldehyde on physiological responses after ethanol ingestion in young healthy men with different ALDH2 genotypes They get more facial flushing and a faster pulse after drinking.17PubMed. The acute effects of ethanol and acetaldehyde on physiological responses after ethanol ingestion in young healthy men with different ALDH2 genotypes These reactions track levels of the byproduct, not blood alcohol.18PubMed. The acute effects of ethanol and acetaldehyde on physiological responses after ethanol ingestion in young healthy men with different ALDH2 genotypes
A red face and neck often appear within minutes of a small drink, sometimes followed by a pounding heart, nausea, or headache. Because it happens after so little alcohol, it points to your body handling the byproduct poorly rather than to heavy intake.
If this is you, treat it as a reason to drink less, not something to hide. Medicines that mask the flushing don’t remove the toxic byproduct. If reactions are severe, ask a doctor.
Chills From Alcohol Withdrawal
Long-term heavy drinking makes the brain adjust its chemistry to work with alcohol always present.19PubMed Central. Alcohol withdrawal syndrome: mechanisms, manifestations, and management Stopping suddenly leaves the brain overexcited.20PubMed Central. Alcohol withdrawal syndrome: mechanisms, manifestations, and management The body’s stress systems go into overdrive, causing shakes, sweats, chills, and a racing heart.21PubMed Central. Alcohol withdrawal syndrome: mechanisms, manifestations, and management This is alcohol withdrawal, and it can progress to seizures and severe confusion.22PubMed Central. Alcohol withdrawal syndrome: mechanisms, manifestations, and management
A hangover follows one heavy session, while withdrawal follows weeks or longer of near-daily heavy drinking. Withdrawal symptoms often begin within roughly 6 to 24 hours after the last drink. They can worsen over the first day or two, rather than easing as a hangover does. Needing a drink to stop the shakes is a strong sign of physical dependence.
After long-term heavy drinking, don’t try to stop suddenly on your own, because withdrawal can turn dangerous. Talk to a doctor first; medically supervised detox can make stopping much safer. Seek emergency care for a seizure, hallucinations, or severe confusion.
Chills That Need a Doctor
Heavy drinking is a leading cause of pancreatitis, inflammation of the pancreas. Get care right away for severe or worsening belly pain, nausea and vomiting, fever or chills, or a fast heartbeat.23National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Pancreatitis Shortness of breath or yellowing of the skin or eyes are also urgent signs.24National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Pancreatitis These can signal serious infection, inflammation, or a blockage.25National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Pancreatitis
Hangover chills fade over a day, while illness tends to persist or worsen. Belly pain that spreads to the back after drinking is a warning sign of pancreatitis. Being unable to keep fluids down for hours needs medical help, since dehydration can worsen quickly.
Medicines are another thing to check. Alcohol can interact with many common ones, including sedatives, pain relievers, and antihistamines, and combining them can deepen drowsiness and confusion. Check labels or ask a pharmacist before drinking while on medication.