Hot under the blanket, cold out of it. The hangover morning often cannot decide what temperature it is, and that indecision is itself a clue: temperature regulation is one of the systems alcohol disturbs, and its hangover is a regulation hangover too. This article covers the whole swing. The sweating end has its own article, why hangovers make you sweat, and the trembling end has hangover shakes: what trembling means.
What does alcohol do to temperature control while drinking?
It decouples feeling from fact. Vessel widening sends warm blood to the skin, producing the familiar flush and glow, while the body's heat escapes faster into the room. The drinker feels warmer as they become, in heat terms, poorer. Swift and Davidson (1998) place this vessel effect among alcohol's core physiological actions, alongside the diuretic effect behind hangover thirst and dry mouth: what is going on. Cold environments make the gap dangerous, which is why alcohol and cold exposure are a recognised risky pairing in safety guidance generally. None of this is the hangover yet; it is the disturbed starting point the hangover inherits.
Why does the next morning swing between hot and cold?
Layer the hangover state's known parts. Sleep was fragmented, per the sleep literature behind alcohol, sleep, and the hangover morning, and temperature regulation runs on sleep architecture: the second half of an alcohol night is lighter, more broken, and worse at holding a steady thermal state. The rebound arousal described in hangover anxiety: what the evidence says raises heart rate and stress signalling, which reads partly as heat and restlessness. Penning and colleagues (2010) propose an immune response with cytokine changes tracking severity; immune signalling is how the body produces fever and chills in illness, so a mild echo of that pattern during hangover is plausible, and this article keeps it at plausible: the named hangover sources do not establish a true fever as a standard hangover feature, and this site does not claim one.
Are chills during a hangover the same as the shakes?
Related morning, different symptom. Chills are the felt sense of cold with the body's warm up responses, shivering included, engaged. The shakes covered in hangover shakes: what trembling means are tremor, a fine shaking of the hands and body that sits closer to the nervous system rebound, and in heavy regular drinkers can mark early withdrawal. A hungover person can have either or both. The safety rule differs by company they keep: chills with a measured high temperature, or shaking with agitation, racing heart, and heavy sweating in a regular heavy drinker, both leave hangover territory and need medical advice, the second urgently.
What helps, and what is just sensible care?
Dress and redress in layers rather than fighting the swing with extremes. Sip fluids. Rest in a room at a steady, comfortable temperature. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) position governs as always: no proven remedy, time clears the state, usually within about a day per how long does a hangover last. Avoid deliberate heat or cold stress, hot baths to sweat it out or cold showers to shock it away; both load a regulation system that is already behind, and the sweat it out logic is dismantled in can you sweat out a hangover. A thermometer settles arguments the skin cannot: if the reading is a real fever, the morning stops being a hangover morning.
FAQ
Does alcohol raise or lower body temperature?
It makes skin feel warmer by widening skin blood vessels while increasing heat loss, per Swift and Davidson (1998). The feeling and the heat balance point in opposite directions.
Is fever a normal hangover symptom?
A true measured fever is not established as a standard hangover feature in the sources named here. Feeling hot, sweating, and chills are reported; an actual fever should be assessed medically.
Why do I get chills the morning after drinking?
Plausibly the combination of disturbed regulation from the night, fragmented sleep, rebound arousal, and the immune response proposed by Penning et al. (2010). The sources support the layers, not a single proven chills mechanism.
When should temperature symptoms worry me?
Measured fever, violent or uncontrollable shivering, confusion, severe headache, or symptoms persisting beyond the hangover all warrant prompt medical help.
Bottom Line
Alcohol disturbs temperature regulation in both directions: warmth that is really heat loss while drinking, and a hot, cold, unsettled morning after. Manage the swing with layers, fluids, and rest, measure rather than guess when it feels like fever, and let time do the clearing the NIAAA describes.
Sources
- National Institute on Alcohol Abuse and Alcoholism (NIAAA), Hangovers: https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/hangovers
- Swift R and Davidson D, Alcohol Hangover: Mechanisms and Mediators, Alcohol Health and Research World, 1998: https://pmc.ncbi.nlm.nih.gov/articles/PMC6761819/
- Penning R et al., The Pathology of Alcohol Hangover, Current Drug Abuse Reviews, 2010: https://www.researchgate.net/publication/45658910_The_Pathology_of_Alcohol_Hangover