Ask the expert: heat sensitivity

Long, sun-filled days and muggy nights mean summer is well and truly upon us. It may be the highlight of the year for some, but for people with MS summer is not always such a welcome arrival. Rising temperatures can cause MS symptoms to worsen – in the heat, fatigue can become overbearing, the ability to think clearly may be lost and movement and coordination may become more difficult.

The science behind heat sensitivity 

It’s thought that heat sensitivity (also known as Uhthoff’s phenomenon) can happen for a number of reasons in MS. 

Firstly, when your body temperature increases it can affect the speed at which messages travel along nerves that have previously been damaged by MS. The messages travel along the nerve more slowly, and are sometimes even blocked completely, when you get too hot. This results in a noticeable worsening of your MS symptoms. 

Heat sensitivity can also be caused by MS lesions in areas of the brain that control and regulate your body temperature. This can hinder your body’s response to increased temperatures. For instance the message telling your body to produce sweat might not get through properly. 

If you are sensitive to the heat, you should notice your MS symptoms subside once you've cooled down. 

Your tips for keeping cool in the heat 

• Have an ice pack ready in your freezer so you can use it during the day if you get hot. Wrap it in a tea towel before placing on your skin. 
• Choose cold food and drinks, like salads, frozen yoghurts, ice cream, and iced drinks.  
• Get some fans to use around your house. These will keep the air circulating. 
• Stay hydrated by drinking cool drinks throughout the day. 
• Buy a cooling towel. You immerse these in water, wring them out and wrap them around the back of your neck, as the water evaporates it helps cool you down. Or you could dampen a normal towel or flannel with cold water and do the same. 
• Avoid hot tubs! 
• Keep curtains and windows closed in rooms directly facing the sun during the day. This will stop them getting too hot from the greenhouse effect. Open your windows at night when it’s cooler. 
• Soak some sweatbands in water, wring them out, put them in the fridge and then wear them on your wrists and ankles. 
• Put a bowl of ice in front of your fan so the air is cooler. Homemade air con! 
• Try to avoid using the oven for meals as this will heat up the house. 
• Dip your feet in a bucket of cold water. 
• Wear a wide brimmed hat when outside and try to stay out of the sun by finding shaded areas. You could also soak your hat in cold water to keep your head cool. 
• Fill a hot water bottle with ice cold water and put it at the bottom of your bed to keep your bed cool. 
• Put your pillow case in the fridge an hour or so before you go to bed. 
• Consider wearing sports clothing, such as a running top with wicking properties. These tops pull moisture away from your skin and into the fabric, allowing it to dry out quickly and help you regulate your body temperature.