Find out about MS and heat sensitivity

First published: 16 June 2022 Updated: August 2024

Find out about MS heat sensitivity and how you can ‘beat the heat’

UK heatwaves are synonymous with front-page pictures of beaches packed with people enjoying the sunshine, busy beer gardens buzzing with excitement, and long queues of children at the ice-cream van.

But for those with multiple sclerosis (MS) very often the heat can induce a worsening of symptoms, which while usually temporary, is not something that many people look forward to.

Approximately three quarters of people with MS find their symptoms get worse when they are hot. This can happen whilst exercising, in busy or heated rooms, when the weather is hot or at any time when your core body temperature rises.

Why does heat affect my multiple sclerosis?

As MS damages the nerves, when you overheat, the nerve conduction, (messages that travel along the damaged nerves) get slower, meaning that existing or past symptoms can worsen or flare up.

For others, MS can affect the area of the brain that controls temperature regulation in the body. This area of the brain is called the hypothalamus and acts as your internal thermostat. This means the body may not be able to flush, sweat or cool in response to the heat.

If you are unwell or feverish your symptoms can become exacerbated as infections raise the body temperature. Sometimes you may not know you have an infection and wonder why this is happening. This can sometimes be mistaken as a relapse or worsening MS, which is why it is always important to rule out an infection if you are not sure. Once the body recovers from an infection, the body will cool, and symptoms will calm down or return to their previous baseline.

Many years ago, one of the ways clinicians would diagnose MS was to lower someone suspected of having the condition into a hot bath, and if symptoms appeared or worsened, the assumption was made that they had MS.

How can I keep cool?

The MS-UK helpline team ran a ‘Beat the heat – managing MS symptoms in hot weather’ information session at the end of July 2024. During the session we shared some new hints and tips about managing in the heat. The MS community also shared some of their personal tips for successfully managing symptoms caused by heat.

Below is a list of ten top tips that we think you’ll find helpful if you find heat a problem.

Is it the heat, or something else?

Whether you’re newly diagnosed or a veteran MSer, there will be more than one occasion when you ask yourself the question ‘How do I tell if these symptoms are an exacerbation of my MS, a possible relapse, or something else?’

Whilst the summer heat is peaking, it is easy to write off any symptoms you are having as due to exposure to high heat and humidity. However, it is important to rule out the possibility of an infection, too.

Our ‘Am I having a relapse?’ information may help. It is a good tool for helping you listen to your body. If you are not sure what is the cause of your issues or you have an idea that there may be an underlying infection, it is always a good idea to speak with your health professionals.

Cool your pulse points

Your body contains pulse points that assist in your heat regulation function, situated in areas such as your wrists, ankles, the rear of your knees and your elbow crooks.

These are points of your body where the veins are closest to your skin’s surface, allowing you to cool your blood and circulatory system more directly than in other areas. By applying something cool to these areas for 20 minutes or so at a time, such as an ice pack covered with a towel, a cool wet towel or simply a bag of something from the freezer, your body will benefit from the cooling sensation.

Cool your feet

Your feet are home to thousands of nerve endings and play an integral part in helping you to control your body’s temperature. Keeping your feet cool can be a quick and easy way to prevent overheating. For example, fill a bowl or bucket with cold water and dip your feet into it, place a cold damp towel over your feet or spray your feet with cool water.

Use cool ties, scarves and towels

Cooling scarves are simply something cool/cold you tie around your neck, with the impact being a full-body cooling sensation. These simple yet effective ties and scarves are relatively cheap and accessible. Some come with replaceable cooling inserts that need to be frozen and others contain polymer crystals that when soaked in water cools the body through evaporation. If you are interested in buying one, you could try Soo Cool, MediChill, or Ice Collar. There are also many other options available online too.

It is also worth considering an ‘ice towel’ to freshen yourself up and cool down. Ice towels are thin, ultra-absorbent towels made from manmade fabrics that retain moisture and stay cool longer than traditional linens. There are a variety of brands available.

You can also improvise and make use of cooling mats that were originally designed for keeping dogs cool. These pet cooling mats are often made from specialist material filled with water or gel.

Cool clothing

Wearing suitable clothing made of breathable materials is a good idea whilst trying to stay cool. Cotton, linen and rayon are all materials that are breathable and can help your body’s temperature regulation process.

When thinking about your summer wardrobe, choose lightweight, loose clothing and consider the colours you wear, too. Lighter coloured clothes will reflect, rather than absorb, light energy.

When shopping for summer clothes it may be worth adding some wicking clothing to your wardrobe. Wicking refers to a fabric’s ability to move sweat away from the body and into the fabric. The moisture then evaporates on the surface of the material, keeping you dry and allowing your body to cool effectively. Often these types of active wear clothes are designed with sports and outdoor activities in mind.

There are also specialist aids available including cooling vests and other hi-tech solutions. In countries where heat sensitivity is an ongoing issue for the MS community, such as parts of the USA and Australia, there is a wider availability of cooling aid clothing.

Some of the larger specialist retailers and manufactures of wearable cooling aids such as thermappael, Cool Down Australia and Polar Products will ship their products to the UK.

Cool your environment

Keeping your home cool is an effective way to help prevent you from overheating. You can put ice in front of a fan to create an ‘air conditioning’ effect. This helps by circulating air that is cooling from the evaporating ice. It is also suggested that you close the doors of a room you wish to keep cool. Also consider letting cooler night air into your home by opening your windows once the sun has set. Close window coverings that are facing the sun during the day.

Although doing your best with these small hacks may work well enough for a short spell of heat, for those that are profoundly affected by heat it may not be enough. Although expensive, air conditioning is becoming more commonplace as our summers get longer and hotter.

Depending on eligibility, there is a government grant that could possibly help with funding air conditioning for your home. The Disabled Facilities Grant’ (DFG) is grant funding to help with providing facilities or adaptations to a home to meet the needs of a disabled person.

Air conditioning to aid heat intolerance is not a common use of the grant, however, it should be possible. Within the government’s guidance for local authorities, it says ‘Air conditioning or other cooling systems could also be considered where heat exposure can cause or heighten fatigue, numbness, blurry vision, tremors, confusion, imbalance, and weakness as associated with conditions such as Multiple Sclerosis.’

We have written a blog where you can find out more about whether you could get a government grant for air conditioning.

Cool your diet

Staying hydrated is a vital part of helping your body to stay cool. Public Health England’s Eatwell Guide suggests we consume between six to eight glasses of fluids per day.

When your body sweats to keep cool, you lose electrolytes, such as sodium, which our bodies use to help maintain fluid balance and blood pressure. There are healthy foods and drinks that provide a good source of natural electrolytes. This could be coconut water, milk, yoghurt, bananas, watermelon, avocado, chicken and kale.

It may seem obvious to say, but to keep your core temperature cool it may be best to avoid hot meals and instead eat a cold meal. Our team suggest trying a cold salad, a Mediterranean mezze, a Spanish tapas, or even a traditional British ploughman’s lunch.

Some people worry about managing bladder urgency so may be conscious about how much fluids they drink, but even regular sips of icy water will help.

Sleep hygiene and keeping cool at night

For many people with MS sleep hygiene and getting a restful night’s sleep is a challenge. Insomnia, and physical MS symptoms are strong predictors of fatigue in MS.

Quality sleep is often more challenging when thermoregulation is an issue. People can experience night sweats and get broken and interrupted sleep which will then affect functional ability.

We have a blog post all about sleep titled ‘Sleep Tight’. This gives some great hints and tips for a better night’s sleep. The blog post covers the use of light, your circadian rhythm (your sleep/wake cycle), managing your fluid intake and choosing the right foods to help you sleep.

Our blog post also touches on choosing the right mattress, bedding and pillows. It is worth noting that you can buy mattresses, mattress toppers, pillows, bedding and night clothes that are made with cooling in mind.

In the same way that wicking technology is incorporated into clothing, it can also be used with bed linen and pillows. These will draw the moisture and heat away from your body and let it evaporate naturally.

There are also some other small ‘life hacks’ that can be used such as running a (silent) fan in your bedroom and using ice blocks in your bed with the intention of cooling your mattress before sleeping.

Do all you can to reduce stresses and stress response

In some instances, stress and anxiety symptoms may lead to a rise in body temperature. This is called a psychogenic fever as it is caused by psychological reasons. There isn’t a great deal of research on the effect of stress and raising your core temperature, but we know that the physical symptoms of stress, including difficulty breathing, high blood pressure, diarrhoea and nausea can be just as debilitating and often made worse by heat.

There is evidence of the benefits of mindfulness-based interventions’ (MBI) in alleviating stress and anxiety. People practising mindfulness carry less anxiety and stresses about their condition.

Although any mindful practice is better than none, studies have shown that the most benefit is gained through condition-specific support. MS-UK deliver two types of mindfulness courses. Our eight-week Mindfulness-Based Stress Reduction (MBSR) course and our four-week mindfulness course. They run throughout the year.

Plan for heat and be kind to yourself

With careful planning you can try your best to outsmart the sun. As British summers have been hotter and longer than they have been in the past it may be an idea to take inspiration from continental Europe and break up your day.

Avoiding activity during peak heat is why the Spanish take a ‘siesta’ and the Italian’s a ‘riposo’. If you can, completing daily activities early in the morning or after dusk, when the worst of the day’s heat has subsided, may be a good way of pacing your days.

Sometimes it’s not easy to split your day up and take a meaningful break in the middle of the day. Perhaps your working role makes this a challenge. If this is the case it is worth speaking with your employer about flexible working arrangements. This would be classed as a ‘reasonable adjustment’. MS-UK hold some information all about MS and Work, where you can read some good hints and tips for speaking with your employer about your MS and find out more about your rights at work.