Do you find yourself tossing and turning at night because your bedroom feels unbearably hot? Do you wake up exhausted, struggle to get out of bed and find yourself more irritable than usual?
For many people, these may seem like temporary consequences of a hot spell. But psychiatrists and emerging research suggest that extreme heat can affect far more than physical comfort. It can disrupt sleep, drain energy, impair concentration and emotional regulation, and intensify anxiety, irritability, and depressive symptoms.
As Sri Lanka experiences prolonged periods of unusually high temperatures, mental health professionals are warning that the psychological consequences of extreme heat deserve greater attention.
Dr. Rumi Ruben, consultant psychiatrist at the Teaching Hospital, Karapitiya said the continuing hot weather associated with the El Niño phenomenon was contributing to an increase in reported mental health problems.
“Prolonged exposure to the sun increases body heat, which can affect mental wellbeing,” Dr. Ruben said.
“The consequences may extend beyond individual distress.” He said extreme heat could contribute to road rage among motorists and increase tensions within households, potentially raising the risk of domestic violence.
“People already living with psychiatric conditions may be particularly vulnerable, as extreme heat can aggravate existing symptoms,” he added.
Dr. Ruben said children and older adults also require special attention during periods of intense heat. He advised people to limit unnecessary exposure to direct sunlight and drink sufficient water to reduce the effects of heat stress.
Heat Beats Sleep
One of the clearest links between extreme heat and mental health is sleep.
A 2025 study by Lea Baecke and researchers from the Department of Psychosis Studies at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience found that people experiencing extreme heat frequently reported poorer sleep in both quality and duration.
Participants described hot indoor environments as making it difficult to fall asleep and stay asleep. The resulting exhaustion could then affect mood and motivation the following day, it was stated.
One person with lived experience described their bedroom becoming so hot that it felt like a greenhouse. Poor sleep left them feeling significantly worse the next morning, with little energy or motivation to get out of bed.
“The relationship can become a cycle. Hot conditions make sleep more difficult; inadequate sleep contributes to fatigue, irritability, and low mood; and those effects can make it harder for people to cope with the next day of heat,” Dr. Ruben said.
Heat, Stress, and the Brain
Consultant psychiatrist Malsha de Silva of the National Institute of Mental Health (NIMH) said the relationship between heat and mental health was rooted in a combination of physiological and psychological responses.
Studies have found associations between prolonged heat exposure and increased stress and irritability. “Physical discomfort, dehydration and disrupted sleep can also contribute to fatigue and difficulties with concentration and cognitive functioning” she told CIR.
In other words, the psychological effects of extreme heat do not necessarily begin in the mind. They can emerge from a chain of physical responses that eventually affect mood, behavior and cognitive performance, she said.
Usual Coping Mechanisms Disappear
Extreme heat can also take away some of the everyday activities people use to maintain their mental wellbeing.
Going for a walk, exercising outdoors, meeting friends or simply spending time outside can become difficult or unsafe during periods of intense heat.
For people who depend on these activities to manage stress, their sudden absence can remove important coping mechanisms.
The 2025 research noted that extreme heat could restrict access to activities that people normally use to keep their mental health stable.
This matters because mental wellbeing is not maintained solely through clinical treatment. Everyday routines, physical activity, social contact, and time outdoors can all play a role.
When extreme heat forces people indoors and disrupts those routines, another layer of psychological strain can emerge.
Facing Greater Risks
The effects are unlikely to be distributed equally.
People with existing psychiatric conditions may be more vulnerable to worsening symptoms during periods of extreme heat. Older adults and children may also face heightened risks because of their greater physiological vulnerability to high temperatures.
“Those taking regular medication for mental health issues may encounter side effects due to dehydration. Some regular medications include pills with lithium. Due to excessive sweating, and lack of water intake could lead to dehydration and as a result, lithium composition of patient’s body may increase.”
Malsha de Silva, Consultant psychiatrist, NIMH
People who work outdoors, live in poorly ventilated homes or have limited access to cooling may have fewer options for escaping prolonged heat.
For low-income households, extreme heat can therefore become both a physical and psychological burden. Staying cool may depend on access to electricity, fans, air conditioning, adequate housing, and clean drinking water — resources that are not equally available to everyone.
A Growing Climate-Health Concern
The health effects of extreme heat have traditionally focused on dehydration, heat exhaustion, heatstroke, and cardiovascular stress. But the growing body of evidence suggests that mental health needs to be part of the same conversation.
For psychiatrists, the warning signs can be deceptively ordinary.
“Individually, these symptoms may not immediately appear to be heat-related. But when they occur alongside prolonged exposure to high temperatures, they can form part of a broader picture of heat-related psychological stress,” Dr. Ruben said.
For someone lying awake in an overheated room or waking exhausted after another hot night, the problem may not simply be discomfort.
The heat could be affecting how they sleep, think, feel, and cope.