When the Heat Gets Into Your Head

A long heat wave doesn’t only settle in your joints — it settles in your mood. If you’ve felt more anxious, more flat, or more foggy these past weeks, the heat is a real part of the story.

By Dr. Carmela Levy-David · Today’s Mind & Body

This is the last piece in my little series on the heat. We’ve talked about the body in general, and about chronic pain. Today I want to name the part that’s easiest to blame yourself for: what the heat does to your mind. The extra worry. The short fuse. The flat, heavy days. The fog that makes simple things feel hard. If any of that has crept in during these long hot weeks, please hear me — it is not a character flaw. It has real physical roots.

Why heat weighs on mood and anxiety

Your body treats relentless heat as a stressor, and it answers with more cortisol — your main stress hormone. Sustained high cortisol is associated with more anxiety, more irritability, and a lower, flatter mood. Layer on the broken sleep a hot bedroom causes, and the picture gets heavier, because poor sleep alone frays mood and patience the next day.

There’s a quieter loss, too. When it’s genuinely dangerous to be outside, we give up the very things that steady us — daylight, movement, and time with other people. Take those away for two weeks and mood dips almost on schedule. For anyone already living with depression, an anxiety disorder, or bipolar disorder, a long heat wave can make symptoms harder to manage.

The fog is real, too

That “I can’t think straight” feeling has a physical basis. Even mild dehydration makes concentration and memory harder, and shallow, broken sleep robs you of the hours your brain uses to consolidate and reset. Add heat’s general drain on energy, and it’s completely understandable that words go missing and focus slips. You’re not losing your sharpness — your brain is working in hard conditions.

Anxiety’s cruel trick in the heat

Heat can also feed anxiety through the back door. A racing heart, sweating, and breathlessness are normal responses to being hot — but they’re also the exact sensations of a panic response, and for an anxious mind they can be read as alarm, which cranks the anxiety higher. Naming that loop — “this is the heat in my body, not danger” — can itself turn the dial down a little.

This article is for general educational purposes and is not medical advice, diagnosis, or treatment. Statements describe what is generally associated with heat exposure and are not claims to treat or cure any condition. If you live with a mental-health, autoimmune, inflammatory, metabolic, or cardiovascular condition, talk with your physician about managing extreme heat. This is a sensitive topic; if you are struggling, please reach out to a professional or a trusted person, and in an emergency contact your local emergency number or, in the U.S., call or text 988.