Can’t Take the Heat? It Could Be Your Meds.

As we enter summer and enjoy warmer weather, some people may tolerate the heat better than others. Certain medications and health conditions can impair one’s perception or tolerance of heat, increase dehydration risk, or reduce the body’s ability to regulate its temperature.¹ By understanding your risk factors, you can be prepared to tackle the summer heat, and reduce your odds of heat-related illnesses!

Medications That Affect Heat Tolerance

Some medications may impact how you tolerate summer weather by affecting the circulatory system, changing hydration habits, increasing sun sensitivity, and even directly raising your body temperature.²

Dehydration

Hydration is especially important in hot weather and can be negatively affected by certain medications that impact sweating, thirst, and electrolyte balance. Some hydration related side effects and medications include:²

• Increased Urination – Diuretics, antiseizure medications like Oxcarbazepine, thyroid replacement

• Increased Sweating – Selective Serotonin Reuptake Inhibitors (SSRI’s), Serotonin-Norepinephrine Reuptake Inhibitors (SNRI’s), antiseizure medications like Oxcarbazepine

• Decreased Thirst – Diuretics, Angiotensin-Converting Enzyme Inhibitors (ACEI’s), Angiotensin II Receptor Blockers (ARB’s), mood stabilizers

• Electrolyte Imbalance – Diuretics, calcium channel blockers

Decreased Sweating

The body’s main method for cooling down is sweating to dissipate heat through evaporation.³ Medications that reduce sweat or impair your ability to sweat can make you more susceptible to overheating. Some include:²

• Beta blockers

• Antipsychotics

• Tricyclic antidepressants (TCAs)

• Antiseizure medications like Topiramate

• Antihistamines like Promethazine, Doxylamine, Diphenhydramine

Cardiovascular Effects

Some medications can exacerbate reactions to hot weather by decreasing blood pressure and increasing the risk of fainting as a result. Others directly impair the body’s ability to dissipate heat by reducing blood flow near the skin. These include, but are not limited to:²

• Reduced blood pressure, increased fainting risk – Beta blockers, calcium channel blockers, ACEI’s, ARB’s

• Impaired heat dissipation by decreased vasodilation - Beta blockers, anti-platelet medications, stimulants

Sun Exposure

Sunny days mean a greater risk of sunburn, but some medications can further increase your susceptibility by increasing your skin’s sensitivity to sunlight. Medications that may increase photosensitivity can include:⁴

• Antibiotics

• Antifungals

• Antihistamines

• Cholesterol lowering medications

• Diuretics

• NSAIDs

• Estrogens

• Retinoids

Body Temperature

Hot weather is not always easy under normal circumstances, but having an elevated temperature to begin with can put you at a disadvantage. Certain medications can increase body temperature or alter your perception of heat including:²

• Antipsychotics

• Aspirin (when overdosed)

• Stimulants like ADHD medications

Health Conditions That Affect Heat Tolerance

Many health conditions can impair the body’s ability to regulate temperature or increase your sensitivity to heat. Different conditions affect thermoregulation in various ways, and may cause discomfort in the summer months.

Neurological Disorders

Certain neurological disorders like Parkinson’s can reduce the autonomic nervous system’s ability to respond to environmental temperature changes.⁵ Others, like multiple sclerosis, can cause nerves to become more heat-sensitive, increasing symptoms in hot weather.⁶

Mental Health Conditions

Conditions like anxiety or depression can cause the brain to believe you’re in danger, activating a fight-or-flight response. This can cause increased heart rate, respiration, and make you feel hot or flushed.⁷

Thyroid Disorders

Hyperthyroidism is the overproduction of thyroid hormone, which speeds up metabolism. This can result in excess heat production, making hot weather more uncomfortable for those with thyroid conditions.⁸ Hyperthyroidism can be caused by Graves’ disease, thyroid nodules, thyroiditis, excess iodine, and thyrotropinoma.⁹ 

Diabetes

Blood sugar fluctuations as a result of diabetes can affect your perception of temperature. Feeling too hot or sweaty can be a symptom of high or low blood sugar.⁷

Hormonal Imbalances

Menopause can cause hot flashes and night sweats for women as their bodies produce less estrogen with age.¹⁰ Likewise, men experiencing decreased testosterone production with age can experience hot flashes and sweating.¹¹ 

Infections

The body raises its temperature in response to infection, which can make it more difficult to stay cool in the summer.¹² 

Knowledge is power! By understanding the factors impacting heat tolerance, you can be better prepared to beat the heat! If your medications or health conditions reduce your heat tolerance, be proactive and take steps to prevent heat-related illnesses like heat exhaustion and heat stroke. Wear loose, breathable clothing, drink plenty of water, limit outdoor activity, and find shady or air-conditioned areas to cool off.¹³ If you have questions about your medications and how they might affect heat tolerance, talk to our team today!

Sources:

1. https://www.webmd.com/a-to-z-guides/what-is-heat-intolerance

2. https://www.cdc.gov/heat-health/hcp/clinical-guidance/heat-and-medications-guidance-for-clinicians.html#:~:text=Some%20commonly%20prescribed%20medications%20that,SSRIs%20and%20tricyclics%2C%20and%20diuretics

3. https://my.clevelandclinic.org/health/body/sweat

4. https://www.fda.gov/drugs/special-features/sun-and-your-medicine

5. https://www.apdaparkinson.org/article/temperature-dysregulation-and-parkinsons/#:~:text=Dysregulation%20of%20temperature%20as%20a,as%20a%20non%2Dmotor%20symptom

6. https://www.va.gov/MS/TREATING_MS/Whole_Health/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.asp#:~:text=People%20with%20MS%20often%20have,in%20an%20increase%20in%20symptoms

7. https://health.clevelandclinic.org/why-am-i-always-hot

8. https://www.pennmedicine.org/updates/blogs/health-and-wellness/2017/august/thyroid#:~:text=You're%20always%20hot%20or,%25%20energy%20and%2035%25%20heat

9. https://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism

10. https://www.mayoclinic.org/diseases-conditions/menopause/symptoms-causes/syc-20353397

11. https://www.mayoclinic.org/healthy-lifestyle/mens-health/in-depth/male-menopause/art-20048056

12. https://my.clevelandclinic.org/health/symptoms/10880-fever

13. https://my.clevelandclinic.org/health/diseases/22111-hyperthermia