Is It Safe to Smoke Cannabis in Extreme Heat (40+°C)?

Extreme heat presents specific challenges and risks for cannabis users that require consideration regarding both acute and chronic health impacts. Using cannabis during an extreme heat event can lead to a potentially dangerous situation when the air temperature is higher than 40°C (104°F).

How Heat Impacts Your Body

In times of extreme heat, the human body expends extra effort to maintain normal temperature regulation through a combination of perspiration and increased blood volume in the cutaneous (skin) blood vessels. This process stresses the cardiovascular system, reduces hydration, and increases the risk of heat exhaustion or heat stroke when the external heat source gets close to body temperature.

Smoke Cannabis and Heat

When you smoke cannabis while being exposed to heat, many physiological changes occur in your body that increase your risk of heat illness. Cannabis has the ability to affect body temperature regulation by affecting the dilation of blood vessels and masking the initial signs and symptoms of heat illness. THC may also impair your judgement about when you are experiencing dangerous heat-related symptoms.

Cardiovascular Impacts

Cannabis is capable of acutely increasing heart rate, and sometimes blood pressure. Extreme heat causes increased exertion of the cardiovascular system to cool the body. The combination of cannabis consumption and extreme heat increases the workload of the heart and cardiovascular system, and can lead to serious complications for people with underlying cardiovascular disease.

Dehydration

Cannabis and extreme heat can both contribute to dehydration in different ways. Cannabis use can cause dry mouth and even reduce your awareness of thirst while exposure to extreme heat can lead to fluid loss through perspiration (you must sweat and not perspire). A combination of smoking cannabis and heat exposure will greatly increase your risks of suffering dehydration.

Safer forms of use and guidelines to follow

If you choose to smoke cannabis during extreme heat, it may be prudent to use other forms of cannabis consumption, such as edibles or vapour-based products which have less respiratory irritants than smoking. Quite obviously, stay in air-conditioned places and drink lots of fluids, but try to discover ways to avoid engaging in outdoor activities during peak heat. The hottest part of the day will typically be between one and four pm. You should also check yourself for indications of heat-related illness, such as dizziness, nausea, or just feeling too tired.

When to avoid cannabis in hot conditions

If you have a cardiovascular condition or take medications that can impair your ability to regulate body temperature, or will be engaging in outdoor activities in extreme heat for prolonged periods, you should consider not smoking cannabis at all during extreme heat. Population sub-groups that need to be particularly careful about the combination of cannabis use in extreme heat are elderly or people suffering from chronic disease.

The most appropriate action for yourself during an extreme heat wave would be to just wait to use cannabis until it cools to some reasonably safe temperature, and put your health and safety first, even if consuming recreational substances (cannabis) is not in the best interest of your health.