Why chronic illness + unhinged weather = a bad time
If you live in an unpredictable climate and you barely function in summer — and cool changes either make no difference, or make you feel worse — this is for you.
This blog is a small rant, some nerdy weather stats, some nerdy physiological info, and then some (hopefully) helpful strategies for surviving the summer.
It’s also me saying… if summer strips you of all of your joy — I see you.
You might learn something about your body, you might find new ways to cope, or it might all be stuff you already know. But this could also be a good resource to share with the people who love you and miss you when you have to become a hermit for 3-4 months a year.
I’ve hated summer for as long as I can remember. Ever since I was old enough to feel self-conscious in shorts (because apparently being pale is offensive) — then I got older, my body got bigger, and I was introduced to a whole new world of discomfort. Now, I have not one but two conditions that hate the heat — Dysautonomia (which for me presents like POTS) and Fibromyalgia.
I will be focusing on these two conditions in this blog, but if you have ME/CFS, hEDS or really anything that messes with your internal thermometer, there might be something helpful here for you, too.
The nerdy weather stuff
The one saving grace of summer here in Melbourne used to be that it didn’t get humid, and there was always a cool change just around the corner. “At least it’s dry heat,” we’d say. “The cool change is coming soon!” we’d say.
While the latter is still true — this is no longer a dry place to live.
In January 2026, we had 18 days over what is considered a “comfortable” level of relative humidity.
Melbourne. Please. We did not sign up for this.
Then there’s the volatility of our climate. It’s something Melbourne is known for, but let’s zoom in a little more before we jump into why this makes us chronically ill folk feel even more like steaming hot garbage.
Literally my face from mid November to late March. But sweatier.
Still in January 2026…
Daytime humidity peaked at 79% then dropped to 13% — a swing of 66% — not only in the same month, but within 7 days (and in the evenings, as of writing this post in February, we’re still getting up to 98%).
The highest temp was 42.7° — the next day the temperature dropped by 19°C (to 23.6°C).
Here’s a fun little chart comparing Melbourne to one of the most consistent climates on the planet, to illustrate just how unhinged it is.
Now let’s get into the physiology.
This is my 3rd summer with chronic illness, and my first since starting meds for POTS. I’m handing the actual hot days a little better, but it’s still very shit, and the ol’ pattern recognition has kicked in. So, me being me, I researched it. Hard.
1. POTS + heat + humidity
POTSies tend to feel worse in the heat because of three bodily functions that happen in everyone.
Vasodilation: Blood vessels dilate (widen) to send more blood to the skin and release heat from the body. This mechanism lowers blood pressure and reduces the amount of blood returning to the heart and reaching the brain, which can worsen blood pooling in the extremities.
Sweat + blood volume loss: Get hot → body sweats to cool down → body loses fluids → body has lower blood volume.
Humidity reduces the body’s ability to use its in-built evaporative cooling. In drier heat, we sweat → the sweat evaporates → we cool down. If sweat can’t evaporate (because the air is literally wet 🤢), the body struggles to cool and core temperature rises more easily, which increases cardiovascular strain
Because people with POTS have impaired autonomic systems, they’re not coming from a “normal” baseline. The body is already struggling with:
Poor vascular tone (abnormal contraction/dilation of blood vessels)
Hypovolaemia (low blood volume)
Orthostatic intolerance (onset of lightheadedness, fatigue, and fainting upon standing)
We experience these things from standing up, bending over, lifting our arms, digesting food. When we’re up against heat as well? The added demand often means we’re gonna have a bad time.
2. Fibromyalgia + heat + humidity
Like POTS, Fibromyalgia is also associated with autonomic irregularities — but it’s more widely understood as a condition involving altered central processing of pain and sensory input (hypersensitivity to light, sound, smells and temperature).
This is described as central sensitisation.
Things like bright lights, loud noises and high temperatures aren’t just “unpleasant” or “uncomfortable” with Fibro — it can feel overwhelming, disproportionately intense, and often very painful. For me, I get searing pain right through my eyeballs when the “big light” is on during a flare. And once I’m hot, I’m hot.
Heat is one thing, but many people with Fibromyalgia report worsening pain and fatigue in humid weather, too.
It doesn’t just feel gross — it creates a constant, low-level sensory assault — sticky skin, swelling sensations, perceived heaviness, and feeling like you’re “suffocating”.
This increase in physical discomfort and sensory load can amplify central sensitisation further.
Then there’s sleep, which is a widely reported issue for Fibro patients.
Hot nights → even worse sleep than usual → increased pain sensitivity → even worse sleep → lower baseline/tolerance to triggers → repeat.
Sleep is one of the few things that helps to regulate central sensitisation — and summer can take that away.
These conditions and symptoms are enough to manage on their own. Put them together? They don't just add up, they compound.
3. When it’s multiplicative
Here’s where it gets really fun.
POTS: Cardiovascular instability, orthostatic stress, tachycardia
Fibro: Amplified pain, sensory overload, sleep disruption
Combine them and you get:
Higher heart rate → more fatigue
More fatigue → worse sleep
Worse sleep → even more fatigue + increased pain
Increased pain → less physical activity
Less physical activity → even more fatigue
Deconditioning → lower orthostatic tolerance
Essentially, we end up stuck in multiple symptom cycles.
4. Why cool changes rarely mean relief
Unfortunately, when you live somewhere with wildly fluctuating weather, it’s near impossible to reach a stable baseline like you might in the cooler months.
With drastic and fast swings in temperature, humidity, and barometric pressure — our systems are scrambling to catch up.
Our autonomic nervous system then has to go “oh, okay – constrict the blood vessels, we’re cold now!”. Rapid shifts demand another round of vascular adjustment, and with autonomic dysfunction, that adaptation isn’t always smooth or immediate. Often, before it can happen… it’s hot again.
If the environment around us keeps shifting, we can’t fully recalibrate until we get a solid stretch of consistent weather.
By the time we start to feel a little closer to our baseline, the weather pulls another sneak attack on us and we’re back at the start of the cycle.
So, how do we get through it?
It’s important to note, that even if your house feels cool and dry, your body still responds to things like humidity and barometric pressure outside. Your body might also be experiencing a bit of a “build up” of symptoms. So while cooling your living environment is obviously helpful and ideal — you’ll probably want to use multiple tools and strategies.
Physiological supports
The big one! Aggressive fluid intake: Including water and electrolytes. This will help to increase your blood volume and make it easier for your heart to pump it to where it needs to go. Click here for a recipe to make your own electrolytes — the markup on pre-made is wild.
Cooling vests / ice packs
Icy poles
Cool yourself down as much as possible before you shower
While showering, gradually reduce the warm water and finish cold
Sit in front of a fan while your skin is still wet
Use compression garments if tolerable in heat — Funky Socks rule and regularly have sales.
Cooling blanket / pillows — Not cheap, but I highly recommend the Oodie cooling blanket, and have a fan aimed at it for 20-30 mins before getting into bed. It’s deliciously cool. And I’ve heard good things about Kmart’s cooling pillows.
Environmental hacks
Blackout curtains
Portable aircon / fans — I recently got this fan, it’s super powerful and has a remote and sleep timer
Dehumidifier
Air purifier + fan combo
Activity modifications & pacing
Seasonal capacity planning
Lower expectations in the hotter months
Assume you’re going to need more recovery than usual, and allow yourself that extra time
Plan your appointments and other commitments so they’re spread out across the week/month
Check the weather forecasts regularly
Time activity before the hottest part of the day
Plan buffer days after extreme weather
Taking gravity breaks where possible — getting up from your desk/wherever to lay down with your feet elevated
In summary…
Summer isn’t “uncomfortable” when you live with autonomic dysfunction or central sensitisation. It’s not just sweat and annoyance. It’s cardiovascular strain, fluid shifts, sensory overload, sleep disruption, and a nervous system that never quite gets to settle.
And when you live somewhere volatile, where your body never gets a consistent stretch of weather, you’re adapting constantly. Your nervous system is doing overtime in a climate that keeps moving the goalposts.
So use the whole toolbox. Lower the bar. Plan as best you can.
And if you’re counting down to April like a kid waiting for Santa… same.
