We’ve just come through another brutal stretch of heat in Brisbane. Multiple days above 38 degrees, overnight minimums that barely dipped below 25, and that particular kind of humidity that makes you feel like you’re wearing a wet blanket.

Everyone talks about the physical risks of extreme heat — heatstroke, dehydration, cardiovascular stress. But there’s a growing body of research showing that heat doesn’t just affect our bodies. It changes how we think, feel, and cope.

And given where climate trends are heading in Queensland, this is something we need to start taking seriously.

The Research Is Clear

A 2024 study published in The Lancet Planetary Health analysed emergency department presentations across Australia and found a significant increase in mental health-related presentations during heatwave periods. Admissions for anxiety, mood disorders, substance use, and self-harm all rose during sustained high temperatures.

This isn’t just correlation. There are plausible biological mechanisms. Heat disrupts sleep — and poor sleep is one of the most reliable triggers for mood disturbance. High temperatures also increase cortisol levels and impair thermoregulation, which can exacerbate existing mental health conditions.

Certain medications commonly prescribed for mental health — including lithium, antipsychotics, and some antidepressants — can affect the body’s ability to regulate temperature. People taking these medications are at higher risk during extreme heat, and many don’t know it.

Who’s Most Affected

Heat doesn’t affect everyone equally. The people most vulnerable to heat-related mental health impacts include:

Older Australians, particularly those living alone without adequate cooling. Social isolation combined with heat creates compounding risk.

People with existing mental health conditions. If you’re already managing anxiety or depression, extreme heat can worsen symptoms and make it harder to maintain the routines that keep you stable — exercise, sleep, social connection.

Outdoor workers. Construction workers, landscapers, agricultural workers, and delivery drivers are exposed to heat for extended periods. The cognitive effects of heat — reduced concentration, impaired decision-making, increased irritability — create safety risks as well as mental health risks.

People experiencing housing insecurity. Not everyone has access to air conditioning, adequate insulation, or even shade. For people in older housing stock or those experiencing homelessness, extreme heat isn’t a discomfort. It’s dangerous.

What I’ve Noticed in Brisbane

This isn’t just abstract for me. I live and work here. And during the worst of the recent heat, I noticed real changes in myself and the people around me.

Sleep quality dropped. Several of my yoga students mentioned feeling more anxious than usual. Friends described a kind of low-grade irritability that wouldn’t shift. One mate who works in construction told me his crew was snapping at each other by midday.

There’s also a subtler effect that’s harder to measure: a sense of dread. For a lot of Queenslanders, each new heatwave comes with an underlying awareness that this is part of a pattern, and the pattern is getting worse. Climate anxiety isn’t just about future projections. It’s about what you’re living through right now.

The work being done by technology firms to improve climate resilience modelling is promising, but the mental health dimension of climate adaptation still gets far less attention than the infrastructure side.

Practical Steps for Heat and Mental Health

Protect your sleep. This is the single most important thing during a heatwave. Use fans, wet towels, or cooling mats if you don’t have air conditioning. Sleep in the coolest room of the house. Take a cool shower before bed.

Stay hydrated, but also stay connected. Check on people around you — particularly older neighbours or friends who live alone. A text or a phone call costs nothing and can make a genuine difference.

Adjust your routine. If you normally exercise outdoors, shift it to early morning or after dark. If the heat is making it impossible to do your usual activities, give yourself permission to scale back. This is not the time for pushing through.

Monitor your mood. If you notice increased irritability, difficulty concentrating, disrupted sleep, or heightened anxiety during a heat event, take it seriously. These aren’t personal failings — they’re predictable responses to environmental stress.

Know your medications. If you take psychiatric medication, talk to your GP or pharmacist about whether your medication affects heat tolerance. This is especially important for lithium, which requires careful hydration management.

The Bigger Conversation

Climate and mental health are deeply connected, and we need to get better at talking about both together. Heatwaves aren’t just weather events — they’re public health events. And mental health needs to be part of the response.

Queensland’s public health messaging around heat is improving, but it still tends to focus on physical symptoms. We need to expand that to include psychological impacts and make sure people know that struggling mentally during extreme heat is normal and valid.

We can’t control the weather. But we can be more intentional about how we prepare for it and how we look after each other when it hits.

Stay cool out there. And if you’re not coping, reach out. Beyond Blue is available on 1300 22 4636, and Lifeline on 13 11 14.