Co-exposure to Wildfire Smoke and Heat
This section of the course covers the following topics:
• What can happen
• Who is at risk
• Symptoms of exposure to smoke and heat
• Reducing exposure to smoke and heat
In recent years, there has been an increasing trend in the number of days impacted by wildfire smoke (Burke et al. 2023; Childs et al. 2022). There has also been an increasing trend in heat waves defined as multiple days of unusually high heat. Recent scientific evidence suggests that exposure to both smoke and heat at the same time may be much worse for people’s health than exposure to either of them alone.
When temperatures are hotter than usual, the body may not be able to cool itself fast enough, leading to heat-related symptoms and illnesses like heat rash, heat stroke and death. High humidity, high nighttime temperatures, alcohol use, prescription drug use and sunburn might increase a person’s risk of developing a heat-related illness. See the Centers for Disease Control and Prevention (CDC) websites About Heat and Your Health and People at Increased Risk for Heat-Related Illness for more information.
People who are at increased risk from the health effects of wildfire smoke are also likely at increased risk from heat. This includes people with heart or lung disease, older adults, children and teenagers and pregnant women. People who spend more time exposed to wildfire smoke and heat (such as outdoor workers and unhoused people), people who can’t reduce their exposure to smoke or heat indoors (such as people without air conditioning) and people exercising outdoors are also at increased risk.
Additionally, people who take certain medications, such as those for depression, seizures, or poor circulation or some people with mental illness, for example schizophrenia, are at increased risk from extreme heat but have not been identified as being at greater risk from smoke. See the CDC website Heat and Medications - Guidance for Clinicians.
Symptoms of exposure to smoke and heat
Smoke can cause a range of health effects, including less serious effects such as eye, nose or throat irritation, coughing or wheezing that resolve when the air clears. If your patients have these symptoms, recommend they go somewhere with cleaner indoor air or wear a well-fitting N95® respirator when outdoors. See the Wildfire Guide fact sheet Protect Your Lungs from Wildfire Smoke and Ash for more information.
Smoke may also cause severe health effects such as difficulty breathing or heart problems. Educate your patients about these severe problems. Encourage them to seek medical attention if these problems occur. See EPA’s Fires and Your Health and CDC’s How Wildfire Smoke Affects your Body for more information. Most healthy adults and children recover quickly from short-term (hours to days) exposure to smoke and will not experience long-lasting health effects.
Early symptoms of heat-related illness include feeling unwell, headache, sweating and thirst, nausea, lightheadedness, fatigue, heat rash and muscle cramps. If someone has these symptoms, they should go somewhere cool and sip water, preferably with electrolytes or have a salty snack, until the symptoms improve. They should seek medical attention if the symptoms do not improve.
People need immediate medical attention if they have more serious symptoms of heat-related illness. More serious symptoms include fainting or loss of consciousness, weakness, extreme fatigue, severe nausea, vomiting, seizures and difficulty speaking. See CDC’s About Heat and Your Health for more information.
Reducing exposure to smoke and heat
Tips about reducing exposure to smoke and heat are discussed in the following sections. It is important to note that some smoke exposure reduction measures can have unintended consequences. For example, closing windows and doors to keep smoke out of the house can increase exposure to heat. For specific tips about reducing exposure both outdoors and indoors, see the Protect Yourself from Smoke and Heat fact sheet.