The Relationship Between Heat & Multiple Sclerosis Symptom Flares
Hotter temperatures can mean increased symptom flares for many MS patients. Thankfully, these heat-related worsening of symptoms are only temporary and improve once the body cools down.
Watch the video: The Relationship Between Heat & Multiple Sclerosis Symptom Flares
Why MS Patients Are Sensitive to Heat
Multiple Sclerosis (MS) is a neurological disorder that progressively damages the protective sheath around nerve cells (myelin) in the spinal cord and brain. The damage slows down nerve signals, and research shows that heat can further slow down these signals.
Data shows that 60-80% of MS patients experience worsening symptoms, including fatigue, pain, and the ability to think, focus, and remember when exposed to heat.
The worsening of symptoms or pseudoexacerbation that results from becoming overheated either from physical exertion or due to environmental conditions is known as Uhthoff’s phenomenon, which can exacerbate other MS symptoms, such as:
- Blurred vision
- Muscle weakness
- Tremors
- Problems maintaining balance while standing or walking, which can lead to an increased risk of falls
- Bowel and bladder problems
- Numbness in the extremities

Ways to Minimize the Impact of This Year’s Summer Heat
The heat-related worsening of symptoms experienced by many multiple sclerosis patients differ from MS relapses because they don’t cause new damage to the central nervous system and usually subside when the body cools down.
Therefore, staying cool in the sweltering summer months is vital to keeping these symptoms in check. Here we list some ways to help you stay cool.
- Try to stay in an air-conditioned environment during peak heat and humidity hours.
- Wear lightweight, loose-fitting clothing made of natural fibers such as cotton, which provides more breathability.
- Wear hats and stay in the shade as much as possible during the hottest parts of the day.
- Drinking cold beverages and eating popsicles can help you regulate your body temperature.
- Invest in specialized cooling accessories such as cooling vests, neck wraps, and bandanas when exercising, or when you know you will need to spend some time outdoors in the heat.
- Take cold showers or baths.
- Spritz cold water on your face, neck, and arms to help regulate your body temperature.
- Eat more cold dishes such as salads, fresh fruits, and cold soups like gazpacho. This will minimize your heat exposure while cooking.
- Invest in cooling sheets, pillows, and pillowcases to help you stay cool while you sleep.
- Replace incandescent lights with LED bulbs that produce less heat. Turn off unnecessary lights and electronics you are not using, as these can increase room temperature.
- Exercise safely – exercise early in the morning or at night. If possible, go for a swim in an unheated pool.
- Carry a portable fan for those times you can’t escape the heat.

Managing your MS symptoms is difficult, especially under extreme temperatures. Speak to your doctor if you don’t see any heat-related symptom improvement after cooling down, as this could indicate a disease flare-up rather than temporary worsening symptoms.