Editor’s Note: NWS Celebrates the important work of our WRN Ambassadors in helping communities address the impacts of extreme weather. CVS Health, a WRN Ambassador, is helping to educate the public about the impacts of extreme heat on health. NWS is not affiliated with and does not endorse specific products and services provided by CVS Health.
Extreme environmental events, such as heatwaves, are increasing in both frequency, duration, and severity. Major U.S. cities experienced an average of 2 heat waves per year in the 1960s, but are now experiencing more than 6 per year. The average heat wave season is 49 days longer than it was in the 1960s.
Heat is one of the leading causes of weather-related deaths in the United States and contributed to approximately 120,000 emergency department visits due heat-related illness in 2023. Certain prescription drugs and over-the-counter (OTC) medications make this danger even greater. Sixty percent of American adults are currently taking at least one prescription drug, and a quarter report that they take four or more prescription medications. Medications can increase the risk of heat-related illness, and even death, by impairing the body’s response to heat, including the ability to sweat, the rate of blood flow and the rise in base body temperature.
Drugs that can increase the risk of heat-related illness*
| Type of Medication | How it impacts |
|---|---|
| ACE inhibitors | Increase the risk of dehydration, impact kidney function, limit the body’s ability to redirect blood flow |
| Anticholinergic drugs | Inhibit sweating, reduce blood flow to skin, increase the risk of heat-related illness during exercise |
| Antipsychotic drugs (e.g., neuroleptics) |
Combined anticholinergic and central thermoregulatory effects |
| Antipsychotic drugs (e.g., thioxanthenes, phenothiazines) |
Increase base body temperature |
| Antidepressants (e.g., SSRIs) |
Increase sweating, increase risk of dehydration |
| Antidepressants (e.g., tricyclic antidepressants) |
Decrease sweating, interfering with the body’s ability to cool off |
| Diuretics | Impacts fluid balance in the body |
*Note: list is not exhaustive
Certain populations are at greater risk
Certain populations are especially vulnerable to extreme heat, such as 65+ and those with chronic conditions. More than 85% of the U.S. population age 65+ have at least one chronic condition and are taking multiple heat sensitizing medications. Older patients with chronic conditions are at heightened risk for heat-related hospitalization – even in the absence of extreme heatwaves.
Heat also impairs the efficacy and delivery of medicine
Heat also impairs a medical device’s ability to deliver a drug and the potency of the drug. For example, insulin efficacy can be decreased when exposed to high temperatures. For patients such as those who use inhalers, extreme temperatures outside of the manufacturer’s recommended storage conditions have been shown to impact the device’s ability to appropriately deliver the drug. Heat can also impact the performance of devices used for medical treatment, such as blood sugar monitors, insulin pumps, and test strips.
Innovating to support the health and safety of vulnerable communities
As a WRN Ambassador, CVS Health is committed to addressing the convergence between these extreme environmental events, especially heat and vulnerable communities.
For example:
The health impacts of environmental events are becoming a pervasive challenge. Climate-induced changes to extreme heat have the potential to increase emergency department visits and hospitalizations, particularly in populations with preexisting conditions and who live in vulnerable communities. Some of these health impacts can be averted; as a WRN Ambassador, CVS Health is proactively supporting providers, patients, and members in response to extreme environmental events.
Daniel Knecht is CVS Health's Chief Clinical Innovation Officer, focusing on the evolving landscape of therapeutics and advancing clinical strategies for improved patient care. He holds a joint M.D. and M.B.A. from Weill Cornell Medical College and teaches as an associate clinical professor at Mount Sinai West. Dr. Knecht is a Fulbright scholar and a board member of the Foundation of CUNY School of Public Health.
