Hot Enough to Break: How Heat Exacerbates Mental Illness

We talk about how heat affects the body.
We talk about dehydration, exhaustion, sunburns, and sluggish afternoons.
But we rarely talk about what heat does to people already navigating mental illness.

The truth? Heatwaves don’t just make everyone irritable — they can destabilize people with psychiatric conditions. And in a warming world, this is more than an inconvenience — it’s a public health threat.

Why Heat Is a Mental Health Risk Multiplier
People with anxiety, depression, bipolar disorder, PTSD, or schizophrenia often live with delicate neurological and hormonal balances. When heat disrupts those systems, it can trigger:

• Worsening of anxiety and panic symptoms
• Mood dysregulation in bipolar disorder
• Disrupted sleep cycles, fueling instability
• Increased irritability, impulsivity, or suicidality
• Psychotic episodes or disorientation

We’re not talking about “just being a little moody.” We’re talking about episodes that land people in the hospital.

Neurochemical Chaos: What’s Actually Happening in the Brain
Here’s how high temperatures wreak havoc on the mental health system from the inside out:
1. Dysregulated Thermoregulation in the Brain
The hypothalamus helps regulate both body temperature and emotional responses. In high heat, it works overtime — and emotional self-regulation can suffer.
2. Medication Interference
Many psychiatric medications (e.g., antipsychotics, mood stabilizers, antidepressants) impair thermoregulation or hydration — making it harder for the body to stay cool and increasing the risk of overheating or heatstroke.
Some medications also have photosensitivity side effects, increasing sun and heat sensitivity.
3. Sleep Disruption Spirals into Symptom Flare-ups
Sleep loss (common during hot nights) is a known trigger for mania, depression, and anxiety. It reduces your ability to cope with stress and increases sensitivity to emotional stimuli.
4. Cortisol and Serotonin Imbalances
High heat keeps cortisol (the stress hormone) elevated longer, while serotonin (the feel-good neurotransmitter) can decrease. That combo = more reactivity, more mood swings, and less emotional cushion.

The Stats We Can’t Ignore

• ER visits for psychiatric symptoms spike during heatwaves
• Suicide rates increase with higher temperatures
• People with serious mental illness are 3–4x more likely to die during extreme heat events — especially those without stable housing or support
• Incarcerated or institutionalized individuals with mental illness face even higher risks

And yet… most mental health treatment plans don’t account for heat at all.

Who’s Most at Risk?

• People taking antipsychotics, lithium, or SSRIs/SNRIs
• Individuals living alone or with poor social support
• Unhoused individuals or those without access to AC
• Older adults with depression or cognitive decline
• People in environments that stigmatize mental illness and prevent asking for help

What Can We Actually Do?
On a personal care level:

• Review medications with your care provider during hot seasons like a temporary dose or schedule changes (do not do this on your own, always consult a physician before making changes)
• Find green-space alternatives to outdoor exposure during heat spikes
• Monitor yourself for mood changes during prolonged heat waves (use a journal to track your moods)
• Normalize “heat breaks” like we do “mental health days”

System-wide or organizationally:

• Build cooling centers or green spaces with mental health support in mind
• Design summer safety plans for people with known vulnerabilities
• Train staff to recognize heat-exacerbated symptoms
• Advocate for climate-informed mental health policies 

Climate is a Mental Health Issue — Not Just an Environmental One
We’re not imagining this.
The heat is rising. The air is heavier. People are struggling to think clearly, regulate emotions, and survive.
And for people living with mental illness, the stakes are higher.
If we don’t talk about it, design around it, and build care systems that account for it — we’re going to lose lives. Not just to heatstroke, but to invisibility.

So as we enter another record-breaking August:
Let’s stop calling people “fragile” when they’re overwhelmed by heat.
Let’s start asking what their brain — and body — might be up against.

Seen this in your community or workplace? What’s helping? What’s missing?
Let’s make mental health climate-resilient — before it has to be crisis-responsive.