15 Aug 2026 4 min read Trail Provisions

Brain Freeze

If you can't stop the pain, can you change what happens next?

Sometimes a dull roar becomes skull-crushing pressure, eye-stabbing pain, hammering at the back of the skull with every footfall. Excruciating is only the beginning.

I've lived with intracranial hypertension for a decade, beginning after an acute spontaneous subdural hematoma with a 16 mm midline shift in 2016. There are no days off. Even temporary reprieve matters.

Cold helps take the edge off pain and cognitive load. I've used everything from cold showers to full-body immersion, along with breathwork, time in nature, and deliberately shifting attention beyond pain.

When I mention cold exposure, I can usually see the reaction before anyone answers.

Cold shower?

Until a few months ago, I hadn't had more than a dozen hot showers in the previous five or six years. Then my autoimmunity took a turn, endocrine chaos got worse, and my margin for stress got smaller.

Cold is a stressor. That's part of why it can be useful and part of why it isn't always useful. I had to back off.

That changed how I think about cold exposure. It isn't inherently good or bad. It's an input, and whether that input is useful depends on how much capacity the system has for stress at that moment.

It also doesn't have to mean an ice bath. There are grades to it: turning the shower down a little, staying there briefly, returning to warm. Gradually easing into cold without the outright shock that makes people say "oh, hell no."

Consistency matters more than any single session: start with 10 seconds, then 20, then 30, and build from there. For me the shift didn't show up until somewhere around a minute and a half.

I eventually landed on the whole shower cold, for whatever duration felt right that day, capped with about 30 seconds of warm to close it out.

The point still isn't to tolerate the most cold. It's to introduce a different stimulus and notice what happens.

For intracranial hypertension, cold may make a bad hour more survivable. It isn't treatment for pressure or vision changes. For migraine, some evidence suggests cold-based interventions can reduce pain during an attack.

What interested me wasn't that cold helped, but why it might help.

Cold triggers a sympathetic stress response. Norepinephrine and other catecholamines rise, changing blood flow, alertness, metabolism, and potentially how pain is processed. There is also intriguing evidence that deliberately manipulating the stress response through breathing and cold can influence immune signaling.

Not evidence that cold treats inflammation or autoimmune disease, but it does suggest that some parts of what we think of as an automatic stress response may be more influenceable than we once assumed.

That's where it gets interesting to me.

I used cold before I knew it was supposed to be a method. I used breath before I knew it was supposed to be a practice. Later, I found the names: Pranayama, Samatha, Tummo, Wim Hof, and started looking for the machinery underneath.

Different traditions, different aims, different meanings, but some recurring levers: breath, temperature, attention, repetition.

Not control. Influence.

The body isn't completely inaccessible to input. Sometimes the most useful thing you can do is introduce a different input and see whether the system responds.

That's the manual override.

Cold is simply one way to find it.

And sometimes the right input is less input.

Safety Note: I brought these practices to my neurologist to review before implementing them. Self-treatment of a serious condition without appropriate risk assessment and safeguards is risky. So yeah, don't be a dumbass!

Not a solution, but management. I'm sharing what I've found: the mechanisms and where the evidence does and doesn't go. It didn't resolve the underlying problem.