Physical and mental health risks from extreme heat

Outdoor activities reduce stress, but safety in high temperatures is paramount.

Walking in nature, jogging, outdoor sports, listening to the birds singing, gardening – these are just some of the ways to relax and unwind from the ever-increasing stressors we face in a stressful and complex world. But with record heatwaves becoming a common health warning, it’s important to find a balance between what relieves stress and what exacerbates it.

Extreme heat and mental and physical health

According to NASA, 2023 will be the warmest year on record, and 2024 is on track to be another record-breaking year. I often write about nature-based activities as powerful stress relievers, but these opportunities can be a double-edged sword, with extreme temperatures, especially this time of year, raising very real concerns about physical and psychological safety.

We’ve all heard about the physical dangers that extreme heat poses, but these risks are often ignored or downplayed by those who value the health benefits and inherent enjoyment of outdoor activities. Last year alone, there were five cases of heatstroke within my relatively small tennis community, several of which required emergency medical treatment. This means that outdoor enthusiasts don’t always recognize or respond to the early symptoms of heatstroke, even though these experiences are easily preventable with simple preparation and education (Centers for Disease Control and Prevention).

Risk Mitigation Strategies

• Schedule outdoor activities during the coolest times of the day.
• Choose light, light-colored, loose-fitting clothing.
• Apply a waterproof sunscreen with a high SPF 30 minutes before sun exposure and reapply regularly during activity.
• Hydrate early and often the day before and throughout the activity.
• Avoid hot or heavy meals before activity.
• Avoid sugary and alcoholic drinks.
• Consider drinking a sports drink to replenish the salt and minerals lost during sweating.
• Check your local news and heat alerts to find out the best times not to be outdoors.
• If you feel overheated, find a place to cool off temporarily. For example, if you start to feel overheated while jogging, take a break at a nearby store or mall to cool down before returning to the hot spot. If there is no air-conditioned space nearby, find some shade to rest and recover.
• Use a cool towel or ice pack to lower your body temperature.
• Higher humidity increases the risk, so take both temperature and humidity into consideration when planning outdoor activities.
• After being outdoors, take a cold shower or bath to cool down.
• Familiarize yourself with the signs and symptoms of heat stroke and how to treat it. (See CDC’s “Signs and Symptoms of Heat Stroke.”)
• Do outdoor activities with your friends.
• Know your limitations and adjust accordingly. Older adults, young children, people with medical or mental illnesses, and people taking certain medications are more susceptible to heatstroke. However, even healthy, fit people can be affected.
• If you start to experience symptoms of heatstroke, take immediate steps to cool yourself down (get into the shade, apply ice or a cold towel, drink small amounts of water, loosen tight clothing, and remove unnecessary clothing).
• If symptoms don’t improve, don’t hesitate to see a doctor. Heatstroke can be fatal. (According to the CDC, about 1,220 people die from heatstroke each year in the United States.)

• If you see someone who appears to be in distress, ask them if they’re OK. One of the signs of heat stroke is confusion, so they may not fully or immediately realize they’re in trouble. Get the person into the shade, follow the cooling down measures listed above, and call for medical help if necessary.

But physical health isn’t the only risk posed by extreme temperatures: researchers have found that high temperatures can have a significant impact on our mental health.

Dr. Amruta Nori Sarma, whose research focuses on the impacts of interconnected extreme weather on mental health, has reported a significant relationship between high temperatures and emergency room visits for a range of mental health issues, including anxiety, stress-related illnesses, mood disorders, substance use, and suicidality, suggesting that “extreme heat is an exogenous stressor that exacerbates people’s underlying mental health symptoms” (Mills, 2024).

The American Psychiatric Association has also warned about the increased risks that heat waves and extreme heat pose to our mental health, citing increases in irritability, depression, sleep disorders, aggression, domestic violence, substance use, suicidal thoughts, and suicide as major problems associated with rising temperatures (2023).

After all, rising temperatures are increasingly affecting our daily lives, and as the climate is changing at an alarming rate, it will only get worse, so we need to start adapting to these inevitable changes.

One way to do this is to look after your physical health and safety while enjoying the many stress-relieving benefits of outdoor activity. By paying attention to your energy levels, pacing yourself accordingly, and listening to your body’s signals, you can greatly reduce the risk of experiencing heatstroke.

Plus, let’s not forget our mental health: studies have consistently found that high fevers contribute to and exacerbate mental health symptoms, an aspect that is less widely known and covered in the media than the physical symptoms. This means that heat becomes an important factor in our increasingly active and complex lives that cannot be ignored, and it is incumbent on us to be prepared and mindful of changes in mood and behavior.