The Connection Between Climate Change and Multiple Sclerosis
- Diksha Joshi
- Aug 1
- 3 min read
A recent increase in hot summer days has led many people to retreat to air-conditioned spaces to escape the heat. For individuals with neurological conditions like multiple sclerosis (MS), this heat can be more than just uncomfortable, worsening symptoms and negatively impacting day-to-day functioning. With climate change increasing temperatures across the globe, the heat issue is becoming more widespread for those with neurological conditions.
Multiple sclerosis is a neurological disease in which the immune system mistakenly attacks healthy cells in the brain and spinal cord. These cells normally produce a protective covering called myelin that insulates neurons and supports efficient communication between brain cells. As myelin deteriorates, these connections break down, leading to a range of symptoms.
Since heat is well-known to exacerbate MS symptoms, this blog explores the connection between rising global temperatures due to climate change with symptom flare-ups in people living with MS.
MS and Temperature Sensitivity
A hallmark feature of MS is heat sensitivity. This is closely tied to fatigue and is often observed through a clinical phenomenon known as Uhthoff’s syndrome, where a person experiences temporary worsening of symptoms such as blurry vision, pain, fatigue, and muscle weakness when exposed to heat.
Because of this sensitivity, managing external heat and internal body temperature from activities like exercise, fever, hot showers, or simply being in a hot environment becomes an essential part of symptom management.
The Climate Change Puzzle
Climate change refers to long-term shifts in temperature and weather patterns. According to the World Meteorological Organization, the past decade has seen the warmest recorded temperatures to date. These changes are not only environmental concerns but also significant public health issues, particularly for vulnerable populations like those with MS, with research showing how such changes are contributing to symptom exacerbations.
What Research Says About MS and Climate Change
Several studies have explored how heat affects people with MS:
A 2006 study found a relationship between higher temperatures and increased emergency department visits among individuals with MS.
Another study showed that people with MS report greater fatigue in the summer months and experience worsening of cognitive symptoms during this time.
In a separate study, walking ability was shown to slightly decline in warmer climates, and average fatigue scores were higher when outdoor temperatures increased.
A 2023 study showed that even though there was no body temperature difference between the control and experimental group, individuals with MS experienced more discomfort and fatigue during the “heat” trail compared with the control group.
In a review paper, 67% of the papers analyzed presented information showing a strong relationship between environmental temperature or heat waves and MS symptom exacerbations including fatigue, cognitive problems, mobility or hospitalizations.
So, Why Does Learning About this Matter and What Can We Do?
Heat sensitivity in MS is a critical and growing challenge affecting 90,000 Canadians and 2.8 million people worldwide. Heat sensitivity not only impacts people with MS, but also those with other neurological conditions such as those with chronic migraines, Parkinson's disease, or fibromyalgia. Having a deeper understanding of this relationship is imperative in developing effective treatments and improving outcomes. By becoming aware, stakeholders can introduce educational interventions and develop strategies like cooling garments, air conditioning, and they can offer cooling swimming pools and sun protection.
References
Shala-Ghaderi Berntsson, S., Reis, J. J., Zjukovskaja, C., Tulek, Z., Kristoffersson, A., & Landtblom, A.-M. (2025). Climate change impacts the symptomology and healthcare of multiple sclerosis patients through fatigue and heat sensitivity: A systematic review. Journal of the Neurological Sciences, 474, 123526. https://doi.org/10.1016/j.jns.2025.123526
