Heat harms the brain more than we think

Temperatures have been rising all over the globe, worsening a number of environmental problems. However, higher temperatures also impact our brains, leading to behavioral and mental health struggles. 

How does heat affect the brain?

The human brain has an optimal operating temperature, and straying outside of it can cause substantial negative effects on its function, according to a Yale School of Medicine study. "Since activity in wires produce heat, all-electric and magnetic stimulation of the brain deposits thermal energy in the brain," said the study. "Even small changes in temperature due to electrical stimulation of the brain less than 1 degree Celsius, could lead to substantial changes in neuronal activity." 

When the brain overheats, it could lead to "memory loss and decreased focus," and can cause "increased irritability, aggressiveness, anxiety and feeling 'brain fog,'" wrote Forbes. "Short bursts of high heat exposure, like sitting in a sauna, are good for you and can even build up your resilience and improve your focus," said Caroline Leaf, a neuroscientist and mental health expert. "However, longer periods of extreme heat are potentially problematic."

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Specifically, higher heat levels can cause neurotransmitter imbalance, which are the "chemicals that transmit signals between nerve cells," and electrolyte imbalance, which "are essential for maintaining proper nerve function, muscle contraction and fluid balance," Forbes continued. "Seeing these dramatic effects on brain activity from small changes in temperature means that we now need to take such small temperature changes into account," said Steven Schiff, vice chair for global health in Neurosurgery at Yale School of Medicine. Warmer temperatures also increase the risk of heat stroke and reduce blood oxygen levels.

What can we expect long term?

This is a problem that is only going to get worse as the climate crisis worsens. "We have to start thinking about climate change as a mental health crisis. If we ignore climate change as a public health threat, we are abdicating our role as health care providers," Robin Cooper, associate clinical professor at the University of California San Francisco and president of the Climate Psychiatry Alliance, told Time. Temperature instability increases the number of suicides.

Additionally, it "impacts the neurotransmitter serotonin, one of our most important mood regulators, closely linked with keeping aggression in check," Time reported. This, along with heightened discomfort from heat leads to increased anger and violence and in turn leads to higher levels of crime, according to the Giffords Law Center.

Children and younger people are "extra vulnerable to heat stress because their bodies are still developing," Wired reported. Because of this, students' concentration in school is lessened and their quality of sleep is decreased. "It turns out when a student experiences a particularly hot year, they score lower on that exam than you would expect given their other test scores," explained Boston University education economist Joshua Goodman. 

"Climate change is now considered the number-one public health concern," Brown University’s Josh Wortzel, told Time. "For us to not be investing more right now in how to understand the impacts of heat on the brain is unfortunate."