Hot weather can affect concentration, mood, and motivation. Extreme heat puts strain on the brain, potentially leading to cognitive fatigue and irritability. Staying hydrated and keeping cool are crucial to protect your brain function during heatwaves.
How Hot Weather Impacts Brain Health and Performance
With temperatures breaking records across the UK, many of us are feeling the effects—not just physically, but mentally too. New insights from neurologists highlight how rising heat can influence our brain’s function, mood, and even long-term wellbeing.
The Science: What Happens to Our Brains in the Heat?
When the weather heats up, our bodies work hard to keep cool. This process diverts resources away from the brain, which can slow down processing speed and reduce mental clarity. Research shows that high temperatures can impair attention, short-term memory, and decision-making. You might notice it’s harder to concentrate, solve problems, or remember things—especially if you’re dehydrated or exposed to heat for long periods.
Emotional Effects: Why We Feel More Irritable
Hot weather doesn’t just make us sluggish—it can also affect our mood. There’s growing evidence that high temperatures are linked to increased irritability, frustration, and even aggression. Disrupted sleep, discomfort, and added stress all play a role, making the brain’s emotional regulation centres more reactive.
Mental Fatigue and Motivation
As your body uses more energy to cool down, there’s less available for cognitive tasks. This can lead to mental fatigue, sluggishness, and reduced alertness. Tasks that require focus or decision-making feel tougher, and motivation often drops—especially if hydration isn’t maintained.
Are There Any Positives?
It’s not all bad news. Warm weather and sunlight can boost our mood and brain health by increasing serotonin and vitamin D levels. People also tend to be more active and social, which benefits mental wellbeing. However, these positives are most noticeable when temperatures are comfortable—not extreme.
Who’s Most at Risk?
People with neurological conditions such as multiple sclerosis (MS), epilepsy, or migraines are especially vulnerable to heat. Even small increases in temperature can worsen symptoms or trigger episodes. These individuals need to take extra care during hot spells.
Long-Term Effects and Adaptation
Chronic exposure to high temperatures can contribute to inflammation, oxidative stress, and vascular issues, potentially increasing the risk of cognitive decline and neurodegenerative diseases. While our bodies can adapt to some extent through heat acclimatisation, this doesn’t fully protect against the cognitive and emotional strain of ongoing heat stress.
Tips to Protect Your Brain in Hot Weather
Stay hydrated: Even mild dehydration affects thinking and memory.
Limit time outdoors: Especially during the hottest parts of the day.
Dress for the weather: Light clothing and shade help keep you cool.
Use fans or air conditioning: Maintain a comfortable indoor environment.
Eat light meals and rest: Avoid heavy foods and take regular breaks.
Prioritise sleep: Good sleep hygiene helps your brain recover.
Extra care for neurological conditions: Follow personalised advice from your healthcare team.
Hot weather can challenge our brains, but with a few simple strategies, you can stay sharp, comfortable, and healthy—whatever the forecast.