Why Working Out Hungover in the Heat May Be Risky

Inflammation may temporarily rise and increase risk of heat illness

Minneapolis—Drinking alcohol the night before physical labor or exercising in the heat causes inflammation in the body to rise and may increase the risk of heat-related illness. Researchers will present their findings at the 2026 American Physiology Summit in Minneapolis. The Summit is the flagship annual meeting of the American Physiological Society (APS).

Working or exercising in hot conditions causes inflammation in the body to increase as part of a normal stress response. However, too much inflammation may contribute to heat-related illness. Drinking alcoholic beverages can also increase inflammation levels, especially from chemicals found in darker drinks such as whiskey, tequila and red wine, or from a toxic compound called acetaldehyde that the body produces as it metabolizes alcohol. In addition, alcohol may irritate the gastrointestinal tract and allow bacteria to leak into the circulatory system, which activates an inflammatory response.

It’s less clear what happens in the body when the two factors—exertion in the heat and alcohol consumption—are combined, but previous research shows that around 30% of construction workers report working with hangover symptoms at least once a month. Alcohol-induced inflammation is usually temporary and resolves over time.

In two separate trials, volunteers walked on a treadmill at varying speeds for four hours, mimicking half of an 8-hour workday. They exercised in a hot room (100-degrees F with 40% relative humidity). In one trial, the participants drank an average of eight standard alcoholic drinks (enough to reach a targeted 0.11 blood alcohol content) the evening before the exercise test, while abstaining from alcohol before the other session.  Blood samples taken after the exercise session revealed higher levels of inflammatory markers when participants had consumed alcohol the night before.

“These findings suggest that drinking alcohol the night before prolonged physical work in the heat may amplify parts of the body’s inflammatory response. More research is needed to determine whether this increases the risk of heat-related illness or affects recovery and immune function,” wrote Jonathan Specht, PhD, corresponding author of the study. “Those who physically exert themselves after a night of alcohol consumption should take extra precautions to protect themselves from heat illnesses, including proper hydration, rest and seeking cool areas such as shade.” 

NOTE TO JOURNALISTS: The American Physiology Summit will be held April 23–26, 2026, in Minneapolis. To schedule an interview with the researchers, conference organizers or presenters, or to request the abstract “Previous Night Alcohol Consumption Alters the Cytokine Response to Prolonged Physical Work in the Heat,” contact APS Media Relations or call 301.634.7314. Find more highlights from the meeting in our Newsroom.  

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