298. Why You Feel Like a Different Person in the Summer With MS

If MS symptoms feel heavier in the summer… or after a hot shower, a walk in the sun, or a workout that didn't used to wipe you out, this episode is for you.

In this episode, I'm walking you through heat sensitivity and heat intolerance in multiple sclerosis (MS). Why heat can make fatigue, brain fog, spasticity, and walking difficulties ramp up, what's actually happening inside your nerves when it does, and what you can do about it. Not in a "just stay inside until October" way. In a "here's the mechanism and here's your plan" way.

Here's what we cover 🔑:

What heat actually does to nerve signals in MS. MS damages myelin, the coating around your nerves that helps signals travel quickly and cleanly. Even a small rise in your core body temperature can slow those signals down further, or block them entirely along nerves that are already working hard to get the message through. That's why heat doesn't create new symptoms so much as it turns up the volume on the ones you already have.

Uhthoff's phenomenon (aka the temporary worsening of MS symptoms when your body temperature rises). This has a name, it's been documented for over a century, and it's not in your head. I'll explain what qualifies, why it's considered a pseudo-exacerbation rather than a relapse for most people, and why that distinction matters for how you respond in the moment.

Why symptoms often ease back down once you cool off. For many people with MS, heat-related changes are temporary and reverse as core temperature drops. Knowing that can take some of the panic out of a bad heat day. It doesn't always mean nothing can be done about it, and it doesn't mean you should white-knuckle through it. It means cooling down is a legitimate intervention, not a rest break.

How to actually cool your core body temperature. Not just "drink water." I'll get specific about pre-cooling before activity, which parts of your body give you the most cooling for the least effort (hands, feet, neck, and face have blood vessels close to the surface that help dump heat quickly), and how cold liquids and ice work from the inside out.

Which cooling products are worth it. Cooling vests, neck wraps, cooling towels, fans, cold packs. Some do real work, some are mostly marketing, and some are worth it only for specific situations. I'll walk through what to look for and how to think about the cost, including the fact that some MS organizations offer cooling equipment programs.

How to modify your exercise routine in hot