Blog: Why hot weather matters for our mental health | Latest News

By Ashton Ntuli, Chief Operating Officer 

Many of us enjoy warm weather, but long periods of high temperatures can affect both our physical and mental wellbeing.

For people already living with a mental health condition, hot weather can sometimes make symptoms harder to manage. It can affect sleep, increase feelings of anxiety or distress, and make it more difficult to cope with everyday life.

The good news is that there are simple things we can all do to stay well in the heat. Understanding how hot weather can affect us means we can spot the signs early, look after ourselves and support those around us.

What we know

Research into heat and mental health is still developing, but there is growing evidence that prolonged periods of very hot weather can affect people's mental wellbeing.

The Royal College of Psychiatrists' guidance on heatwaves¹ highlights that people with mental illness may be at greater risk during periods of extreme heat. They cite studies that have found increases in mental health-related emergency department attendances and hospital admissions during heatwaves.

For example, early evidence from around the world has shown that:

• Emergency department attendances for mental health concerns can rise  by around 8% ² and wider mental health admissions can increase by around 9.7%³
• Suicide risk can increase by around 1–2% for every 1°C rise in temperature, ^3,4 one of the most consistent findings.
• And children and young people can be affected too - research suggests around a 13% increase in mental health-related hospital visits⁵ during extreme heat

Why does heat affect mental health?

Hot weather puts extra strain on the body. When we're too hot, we can become dehydrated, sleep badly and feel physically exhausted.

These changes can affect how we think and even how we behave. Some people may notice they feel more anxious and irritable than usual. Others may find it harder to concentrate or make decisions.

While this is a complex area with many different factors involved, there is growing evidence that prolonged heat can increase risk for some people.

Who may be more affected?

Anyone can struggle during a heatwave, but some people are more vulnerable. This includes people living with severe mental illness and people living with dementia. For anyone experiencing depression, anxiety, bipolar disorder, schizophrenia or dementia, hot weather may make existing symptoms harder to manage, particularly if they are older.

Hot weather can also present challenges for people with learning disabilities, autistic people, people living with long-term physical health conditions, those taking certain medications, and people experiencing alcohol or drug dependence.

Some mental health medicines can also affect the body's ability to regulate temperature or increase the risk of dehydration. If you are worried about how your medication may be affected by hot weather, speak to your mental health care team, your GP or a pharmacist. Don't stop taking prescribed medication unless you've been advised to do so by a healthcare professional.

Looking after yourself and others

Most people can stay well by taking a few simple precautions.

• Drink plenty of water throughout the day.
• Try to keep your home as cool as possible by closing curtains or blinds during the hottest part of the day.
• Avoid strenuous activity during the hottest hours if you can.
• Check in on friends, neighbours or relatives who may be more vulnerable.
• Keep taking prescribed medication unless a healthcare professional advises otherwise.
• If you notice that you or someone else is becoming increasingly confused, distressed, unusually agitated or unwell during very hot weather, seek help early.

Getting help

For the past few years in South West London, we have seen demand for mental health services increase during the summer months. One of our biggest concerns is that people are not getting support early enough. In recent weeks, for example, around 70% of people attending our local A&Es for urgent mental health support had not previously accessed our NHS mental health services.

It is really important that everyone knows that support is available, and that getting help early can often prevent problems from becoming more serious.

For urgent mental health support, call NHS 111 and select the mental health option, or contact the South West London and St George's Mental Health Crisis Line on 0800 028 8000. Both services are available 24 hours a day.

1.    Royal College of Psychiatrists (2024). Heatwaves and mental health. Royal College of Psychiatrists: https://www.rcpsych.ac.uk/docs/default-source/improving-care/sustainability/heatwaves-guidance.pdf?sfvrsn=a20494c8_3

2.    Nori-Sarma, A., et al. (2023). Association between ambient heat and risk of emergency department visits for mental health conditions among US Adults, 2010 to 2019. JAMA Psychiatry. https://pubmed.ncbi.nlm.nih.gov/35195664/

3.    Thompson, R., et al. (2023). Ambient temperature and mental health: A systematic review and meta-analysis. The Lancet Planetary Health, 7(7), e580–e589. https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(23)00104-3/fulltext

4.    Ro, H., Kim, Y., Hashizume, M. et al. (2026). Multi-country projections of temperature-related suicide mortality. Nature Mental Health: https://www.nature.com/articles/s44220-026-00674-w

5.    K., Yan Lai, et al. (2026) Associations of heat exposure with mental health and suicide in children and adolescents: A systematic review and meta-analysis. Nature Mental Health: https://www.nature.com/articles/s44184-026-00190-w