In July 2025, the American Parkinson Disease Association (APDA) hosted movement disorder specialist Dr. Eleni Okeanis Vaou for a discussion on how climate and extreme weather impact people living with Parkinson’s disease.  Dr. Vaou highlighted that rising global temperatures, heat waves, and severe cold aren’t just environmental concerns, they can also influence Parkinson’s symptoms, how well medications work, and a person’s overall well-being.  This webinar is part of the APDA’s “Dr. Gilbert Hosts” series.

One of the most compelling parts of her presentation was a study comparing emergency room visits for people with Parkinson’s in two cities with very different climates:  San Antonio, TX and Boston, MA.  The results showed that extreme weather led to different health crises depending on the location.  In San Antonio, heat waves were linked to more ER visits for falls and urinary tract infections (UTIs), while, in Boston, the cold was linked to more visits for non-neurological issues, like heart conditions.  This highlights how our bodies are stressed in different ways by the environment.

Dr. Vaou provided practical strategies to help us all prepare and stay safe.  Here are some of the key takeaways:

• Hydration is Critical:  Dehydration worsens many PD symptoms, especially low blood pressure (orthostatic hypotension).   Aim for 8-10 glasses of water or electrolyte drinks a day.  Caffeinated drinks like coffee and iced tea don’t count towards this goal as they can be dehydrating.  Consider setting reminders to drink water, just as you do for medications.

• Be Aware of Your Medications:  Extreme heat and cold can change how your body absorbs and metabolizes medication, especially levodopa.  You might feel like your medication isn’t working as well or for as long on very hot days.  It’s crucial to stay on your medication schedule and store your pills at a consistent room temperature (not in a hot car or garage).

• Plan for Extreme Weather:  Check the weather forecast daily.  On days with extreme heat or cold, it’s best to exercise indoors.  Plan your outdoor activities for cooler parts of the day, like the early morning.  Have a “cool zone” in your home and make sure a family member or caregiver can check on you during a heat wave or storm.

• Know the Warning Signs:  Understand the symptoms of orthostatic hypotension (dizziness, lightheadedness on standing, neck pain) and dehydration (dark urine, dry mouth, fatigue).  Knowing what these feel like can help you take action sooner.

• Listen to Your Body’s “Thermostat”:  People with Parkinson’s often have difficulty with temperature regulation (autonomic dysfunction).  It’s common to feel cold when others are hot, or to experience intense sweating.  This is part of the disease.  The best approach is to use simple, practical measures to make yourself comfortable, like wearing socks if your feet are cold, even on a warm day.

This is a new and important area of conversation for our community.  Understanding how the environment affects our health allows us to be more proactive in managing our Parkinson’s.  Dr. Vaou concluded by reminding everyone that there is “no planet B,” and that anything we can do to help our environment is a contribution to our collective health. 

A recording of the webinar is available on the ADPA YouTube channel.

And now, on with my notes,

– Elizabeth

=============================================================================

“Climate, Weather, & Parkinson’s Disease”

Speaker:  Eleni Okeanis Vaou, MD, UT Health, San Antonio, TX

Webinar Host:  APDA (American Parkinson Disease Association)

Moderator:  Rebecca Gilbert, MD, PhD, APDA Chief Mission Officer

Webinar Date:  July 30, 2025 (Rescheduled from June 12)

Summary by:  Elizabeth Wong, Stanford Parkinson’s Community Outreach

Climate Change and Brain Health

Our climate is changing, leading to hotter average temperatures, altered precipitation, and more extreme weather events like floods, droughts, and wildfires. These events have an indirect impact on society through increased air, water, and soil pollution, and changes in food production.

While more research is needed, we know this has an effect on brain health:

• Infectious Diseases:  Bacteria and viruses from tropical regions are moving farther north.

• Neurotoxins:  There is increased exposure to neurotoxins due to climate change.

• Malnutrition:  Drought and changes to the food supply are leading to malnutrition in new areas.

• Stress:  Extreme weather events cause significant physical and mental stress.

Globally, temperatures have been steadily rising since the 1880s, with each recent year being hotter than the last.

The Direct Impact on Parkinson’s Disease

Climate and weather have a measurable effect on people with Parkinson’s:

• Worsening Symptoms:  Exposure to heat waves makes Parkinson’s symptoms worse.

• Increased Hospitalizations:  Temperature variability has been associated with an increase in dementia-associated hospitalizations.

• Higher Prevalence & Mortality:  Higher average temperatures are associated with increased prevalence, deaths, and disability in Parkinson’s disease.

• Pollutants:  Long-term exposure to pollutants like nitric oxide and black carbon are associated with increased Parkinson’s deaths.

Further research is needed to fully understand the pathways for disease exacerbation by climate patterns, but we do know that heat stress and stroke can accelerate neurodegenerative processes.  In neurons, heat stress can cause protein misfolding and aggregation (like alpha-synuclein), which is a hallmark of Parkinson’s.

Furthermore, people with Parkinson’s often have impaired thermoregulation due to autonomic dysfunction.  This means the body struggles to control its internal temperature, leading to issues like excessive sweating (hyperhidrosis) or insufficient sweating (hypohidrosis).

Impact on Sleep and Dementia

Sleep:  Our bodies require lower temperatures for quality sleep. Increased ambient temperature is associated with sleep disruption, poorer sleep quality, and can worsen conditions like sleep apnea.  This disproportionately affects the elderly.  Exposure to extreme weather events like a storm or flood, has led to increased trauma arousability affecting sleep.  Air pollution is related to disrupted sleep; studies have shown increased rates of habitual snoring in children living in more polluted areas.

Dementia:  While the exact mechanisms are still being studied, heat and pollutants are known to cause inflammatory responses in the brain, accumulation of amyloid-beta proteins, microglial activation, disruption of the blood-brain barrier, diminished white matter and total brain volume—all of which are linked to neurodegeneration and dementia.

The Boston vs. San Antonio Study

A study was conducted to compare how extreme temperatures affect people with Parkinson’s in two different climates.

Objective:  To compare emergency room (ER) admissions for Parkinson’s patients in Boston (extreme cold) and San Antonio (extreme heat) between 2020 and 2023.

Hypothesis:  Extreme temperatures would increase ER admissions.

Findings:

• The most common reasons for ER visits overall were falls, urinary tract infections (UTIs), and miscellaneous causes.

• In San Antonio (hot climate):  There was a significant increase in ER admissions for falls and UTIs during heat waves, with temperatures over 90°F.

• In Boston (cold climate):  There was an increase in ER admissions for miscellaneous causes (often non-neurological, like cardiac issues) during periods of extreme cold (below 32°F).

Proposed Mechanisms and Clinical Implications:  Temperature extremes stress the body’s physiological function and can overwhelm the compensatory mechanisms in people with Parkinson’s.  Temperature may alter medication metabolism and efficacy. PD related autonomic impairment affects thermoregulation, blood pressure control, and fluid balance.  The type of health crisis that occurs appears to be location-dependent. This shows that geography should be considered when providing care and advice to patients.

Practical Strategies for Patients

1.  General Awareness and Planning:

• Check the Weather:  Be aware of daily forecasts, especially for upcoming heat waves or storms.

• Stay Hydrated:  This is crucial, especially in the heat.  Dehydration worsens symptoms like tremors,rigidity and orthostatic hypotension (OH). Recognizing OH symptoms and dehydration symptoms can prevent serious complications in PD patients.
  
  Signs of orthostatic hypotension (OH) include dizziness, neck pain, lightheadedness and fainting when standing up and often worsens with heat exposure.  Monitor OH with regular blood pressure checks when changing positions throughout the day, prompt recognition with position adjustment can help prevent ED visit. 
  
  Indicators of dehydration include dry mouth, dark urine, fatigue, increased tremors, and may exacerbate medication side effects.  Tracking fluid intake throughout the day and prompt recognition amount of intake and immediate hydration can prevent ED visits.  Aim for 8-10 glasses of water or electrolyte drinks a day.  Caffeinated drinks like coffee and iced tea don’t count towards this goal as they can be dehydrating.  Consider setting reminders to drink water, just as you do for medications.

• Medication Management:  Stay on schedule, as temperature affects drug metabolism. Store medications at a stable room temperature.

• Environmental Control:  Create “cool zones” in your house.  Cool down the bedroom at night for better sleep.

• Communication: During extreme weather, ensure a family member or caregiver checks in on you.

2.  In Extreme Heat:

• Use cooling vests or fans to stay cool.

• If you have low blood pressure (orthostatic hypotension), know that it will worsen with heat.  Hydrate and check your blood pressure regularly.  If blood pressure is extremely low, talk to your doctor.

• Be mindful of sweating.  If you under-sweat, your body can overheat quickly.  If you over-sweat, you must hydrate even more, and if sweating is excessive there are treatments (anticholinergics or botox can be considered in some cases), so talk to your doctor.

3.  In Extreme Cold:

• Avoid exercising outdoors. Opt for an indoor gym or home exercises.

• Expect muscles to be more rigid and movements to be slower.

• Dress in layers and maintain indoor humidity.

How Temperature Affects Medication (Levodopa)

GI Motility:  In extreme cold, gastrointestinal motility slows down, which can worsen constipation and reduce the absorption of medication.

Dehydration & Blood Pressure:  In the heat, dehydration and low blood pressure can alter the absorption and distribution of levodopa, making it feel less effective.

Circulation:

• Heat causes vasodilation (widening of blood vessels), which can lower the peak concentration of levodopa in your plasma.

• Cold causes vasoconstriction (narrowing of blood vessels), which can impair the delivery of medication to tissues and worsen motor fluctuations.

Metabolism:  Heat stress can increase your metabolic rate, causing you to metabolize levodopa faster, again making it feel like it’s wearing off sooner.

Question and Answer

Q:  Have you seen people with PD feel the opposite of the weather, like feeling chills in hot weather or sweating in cold weather? 

A:  Yes, this is common and part of the autonomic dysregulation of Parkinson’s.  The body’s internal thermostat is off.  The best thing to do is use conservative measures to make yourself comfortable—for example, wear socks if your feet feel cold, even on a summer day.

Q:  How can you exercise safely in extreme heat? Do electrolytes help? 

A:  It is critical to continue exercising.  To do so safely, exercise early in the morning or move your workout indoors to a temperature-controlled environment.  Do not underestimate the weather; it can be dangerous.  Electrolyte drinks are excellent, especially in the summer.

Q:  Can your body’s thirst signals fool you? 

A:  Yes.  You may not feel thirsty even when you are dehydrated.  The best way to overcome this is to make a conscious hydration plan.  Set alarms or use a water bottle with time markers on it to prompt you to drink throughout the day.  If you plan to exercise, be sure to pre-hydrate, hydrate during, and hydrate after.

Q:  Is sweating affected by medication like levodopa? 

A:  Mostly, sweating is controlled by the body’s own autonomic dysregulation (the faulty thermostat).  However, some patients notice they sweat more when their medication is wearing off, so there can be an indirect link.

Q:  At what point is sweating “too much”? 

A:  There isn’t a specific cutoff.  People usually seek treatment when it becomes socially awkward or impacts their quality of life.  If you sweat a lot, the most important thing is to hydrate more, especially with electrolytes.

Q:  What about drinking coffee in hot weather?  Some studies say caffeine is good for PD. 

A:  While some studies show a benefit, you should not use coffee or caffeinated tea as a means of hydration. Caffeine is a diuretic, meaning it makes you urinate more and lose fluids.  You can still drink coffee, but it doesn’t replace water.  Too much caffeine can also worsen tremor and anxiety.

Q:  What is the appropriate temperature to store levodopa? 

A:  The easy answer is that you should store levodopa at room temperature, which is between 68 and 77 degrees, so if someone is storing it at 77 or 78 degrees, that is fine.  However, the best temperature to sleep is roughly around 64-66 degrees, so you may want to turn the thermostat down at night which will help with sleep duration and quality.  

For someone with orthostatic hypotension and symptomatic, they don’t want their house at higher temperature, you want to bring it lower as higher temperatures will decrease blood pressures lower.  Higher temperatures in the 80s in house will make symptoms, metabolism, and levodopa absorption worse.

Q:  What would be the ideal climate for someone with Parkinson’s to retire to?

A:  A more temperate climate where you have the seasons but it doesn’t get too cold or too hot and doesn’t have the extreme variability of temperatures.  If you have a house with very nice cooling and warming then you are fine, but you also have to think about the outdoors and how much time you can spend outside for exercise and hobbies.  Probably somewhere more to the south, but not too hot where you can’t go outside.

Q:  Would you consider constipation medication only during warm weather?

A:  Everything is individualized.  I love this question because it might be coming from someone who knows that their symptoms are related to temperature changes.  If you feel your constipation gets worse with a heat wave, then yes, pre-treat and treat during the heat wave, and then you can stop knowing that at normal temperatures, you’ll feel better and not have constipation.

Q:  Are there medications that can be given to counteract symptoms of poor temperature control in PD?

A:  Education is key.  I tell patients that this is a symptom of Parkinson’s and that it’s normal for someone with PD to feel this because that is what your autonomic nervous system is doing.  Understand how the environment affects the body. 

Also, ensure medications are optimized to reduce “wearing off” times, as fluctuations in motor symptoms can be connected to fluctuations in autonomic functions like temperature control.  Use conservative measures (e.g., heating pads for cold feet) to stay comfortable.