Temperature sensitivity

MS and heat tolerance

The central nervous system is the body’s communication system. It tells the body what to do and how to react to the environment and what’s around us. Complex changes that occur in the nervous system often mean that people living with MS are more sensitive to heat, temporarily worsening symptoms. This is known as Uhthoff’s phenomenon (also known as Uhthoff’s syndrome, Uhthoff’s sign, and Uhthoff’s symptom).

By equipping yourself with the right strategies, you can reduce the impact of this symptom.

When your body gets overheated, it can slow down the messages between the nerves in the brain and other parts of the body. Since MS already damages these connections, it can trigger MS symptoms.

Another possible reason is if you have a lesion (damage to nerves) in the part of your brain that controls temperature regulation, hot or cold weather can then be harder to manage.

For example, MS may interfere with the signals to your sweat glands that help you cool down in hot temperatures, causing you to feel overheated.

Likewise, cold or cool temperatures can also cause symptoms to worsen. While less common than heat sensitivity, cold weather can set off:

• nerve pain and sensory symptoms , such as tingling or numbness
• difficulty moving caused by muscle stiffness (spasticity) or spasms
• fatigue and depression , although this may be due to the lack of sunlight or other factors, rather than exposure to the cold.

• Stay hydrated with water and other cold fluids. Just be sure to limit caffeine, which can increase fatigue.
• Wear lightweight, loose clothing and hats.
• Avoid direct sun and stay in air-conditioned spaces.
• Spray your face and wrists with a mister bottle.
• Keep your home cool.

• Move around to maintain healthy circulation and reduce muscle stiffness.
• Use layers of clothes to keep your body temperature comfortable.
• Warm up with a hot drink or food. Try to avoid alcohol, as while this can make you feel warm temporarily, it can have the opposite effect.
• Keep your home well-insulated by closing windows, doors and curtains.
• Make use of hot water bottles, electric blankets and heat pads. If MS has changed how you feel temperature on the skin, be mindful of protecting your skin from burning.

This page has been reviewed and approved by Executive Manager Client Engagement and Wellbeing Jodi Haartsen. Jodi is a registered MS Nurse who has helped thousands of patients over her 20 years’ experience at Eastern Health MS service in Australia, in several roles including nurse educator, research nurse and nurse practitioner. Jodi is the 2022 winner of the global MS Brain Health Leader Award in the Independent Healthcare Professionals category.