What is Hotboxing?

Lauren Smith
Morgan Blair
Written by Lauren Smith on 28 October 2022
Medically reviewed by Morgan Blair on 05 June 2024

"Hotboxing" is the practice of smoking in a poorly ventilated, enclosed space; letting the air fill with marijuana-laced smoke and contributing to more intense highs, even for people who aren’t partaking.

What is Hotboxing?

How does hotboxing work?

Hotboxing is the practice of smoking a drug, usually marijuana or hashish, in a small, unventilated, or minimally ventilated space. As the smoke has nowhere to go, it creates a more intense high as the drug compound is recycled in the air being breathed.

While secondhand smoke doesn’t deliver the same amount of THC that directly inhaling from a joint, pipe, or bong does, it does contain some. As a result, people get higher faster when hotboxing. Even people who aren’t directly partaking in the drug will also feel the effects—this is known as a ‘contact high.’

Where is hotboxing done?

While cars are the most common venue for hotboxing, marijuana users also hotbox closets, bathrooms, tents, sheds, and even small rooms. Any small, contained space with minimal ventilation can be hotboxed.

In a variant known as a Jamaican or Hawaiian hotbox, smokers hotbox the bathroom while the shower is running. This makes the room hot and steamy. They claim leads to an even more intense high, although there's no evidence to back this up.

Related: Warning signs of weed addiction.

Does hotboxing get you higher?

Yes, scientific studies suggest that secondhand marijuana smoke can get you high, even if you’re not actively smoking.

A 2015 study by researchers at Johns Hopkins placed six non-smokers in a 10-by-13 -foot enclosure alongside six smokers, given 10 joints of high-potency marijuana. In one run of the experiment, the enclosure was well ventilated and in another, it wasn’t. 

In the unventilated enclosure, the non-smokers got high. They felt pleasant, relaxed, tired, and hungry. They displayed mild impairment when performing motor tasks, and THC was also detected in their blood and urine. Yes, just being in a hotbox delivered enough THC to make you fail a drug test.

If you’re actively smoking marijuana, this additional secondhand high will intensifies the effects.

Related: How long do THC edibles stay in your system?

Is hotboxing dangerous?

The US has seen a sea change in attitudes and laws about marijuana over the last decade. The drug is now legal for recreational purposes in 19 U.S. states. However, marijuana is not without risks and hotboxing can amplify them.

Driving while impaired

Cars are the most popular location for hotboxing. Some people even hotbox vehicles while they’re driving or drive immediately after hotboxing. 

This is dangerous because marijuana impairs driving ability. Smoking cannabis has been shown to negatively impact reaction time, concentration, distance perception, hand-eye coordination, and decision-making—all essential for safe driving. You can face DUI/DWI charges for driving under the influence of marijuana.

Even if the person at the wheel isn’t actively smoking, they’ll still feel the effects of marijuana and their driving can suffer. 


When humans are in a contained space, they quickly use up the available oxygen and replace it with their exhaled carbon dioxide (CO2). In air-tight places, this can cause death. 

No place you’re hotboxing is likely to be airtight, but poor ventilation can mean oxygen levels fall below normal while CO2 levels rise. This leads to a build-up of CO2 in your bloodstream, a condition known as hypercapnia. In extreme cases, hypercapnia can be fatal. When hotboxing you might just feel drowsy, disoriented, or lightheaded. You might confuse this feeling with being high.

However, hypercapnia can lead to seizures, respiratory arrest, coma, and death. That’s why you should limit the amount of time you hotbox and take a break by rolling down the car window or leaving the room.


  1. Herrmann, E. S., Cone, E. J., Mitchell, J. M., Bigelow, G. E., LoDico, C., Flegel, R., & Vandrey, R. (2015). Non-smoker exposure to secondhand cannabis smoke II: Effect of room ventilation on the physiological, subjective, and behavioral/cognitive effects. Drug and Alcohol Dependence, 151, 194–202.
  2. Kelly, E., Darke, S., & Ross, J. (2004). A review of drug use and driving: epidemiology, impairment, risk factors and risk perceptions. Drug and Alcohol Review, 23(3), 319–344.
  3. Leonard, J. (2020, October 20). Hypercapnia: Causes, treatments, and diagnosis. Www.medicalnewstoday.com.

Activity History - Last updated: 05 June 2024, Published date:


Morgan Blair


Morgan is a mental health counselor who works alongside individuals of all backgrounds struggling with eating disorders. Morgan is freelance mental health and creative writer who regularly contributes to publications including, Psychology Today.

Activity History - Medically Reviewed on 27 October 2022 and last checked on 05 June 2024

Medically reviewed by
Morgan Blair


Morgan Blair


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