Do you seem to get brain fog in the heat? Is it harder to concentrate and think clearly? Perhaps you’ve noticed that there tends to be more erratic driving on the road, too. The frantic tooting of horns, quick angry swerves and queue pushing. Maybe you also feel that high tension. You certainly wouldn’t be alone.
Many studies have explored the impact of heat on cognitive function in the workplace and education. Consistently it is found that people in the high heat experimental conditions have longer reaction times and increased rates of errors compared to their air-conditioned counterparts [1],[2]. Research exploring the relationship between temperature and emotions is more limited, however there tends to a trend towards higher temperatures and negative emotional experiences.[3] Self-reports of stress and anger increase and there is an increase in aggression[4],[5]. Indeed, studies in the US[6] and Canada[7] have demonstrated on days with hotter weather there are increased emergency room admissions for mental health presentations.
So why do we feel so impacted by the heat?
The answer lies in our central nervous system and a particular region of the brain called the hypothalamus. Our body temperature is regulated by the hypothalamus, which coordinates consequent action across the central nervous system. Here’s for some quick science:
We have thermoreceptors in our skin that detect change in the air temperature around us. When temperature rises or falls past levels we are used to, this triggers a thermoregulatory response. What this response will be, depends on the direction of change in temperature and to what degree. The hypothalamus is constantly balancing external temperature with internal core body temperature. When temperature rises, our hypothalamus can orchestrate bodily temperature regulation by two pathways: (1) physiological thermoregulation which involves things like shivering, skin blood flow and water evaporation (i.e. sweating) and (2) behavioural thermoregulation which may involve us changing our posture, seeking out different environments, or altering our current environment (e.g. looking for shade).
When the hypothalamus determines we need cooling down, it signals for blood vessels to dilate, sending warm blood to the surface of the skin (along with fluids and salts) to allow them to evaporate. We experience this as sweating. Heatstroke occurs when there is nothing left to evaporate and can have severe consequences, even resulting in the death of cells in the brain if we don’t cool and rehydrate. Mice studies have demonstrated that heat stress can lead to inflammation in the hippocampus (area of our brain associated with memory), which authors hypothesise could be a causative factor for memory loss, and neuronal death[8].
Appreciating the substantial coordination of heat regulation within the brain, can help us to also understand how we then come to feel emotionally impacted. Some key things to note are that structures involved in temperature regulation, are also structures involved in emotion regulation. You may have heard of the fight/flight/freeze response. That whole response essentially originates in the hypothalamus. As the hypothalamus is taxed with temperature regulation duties, it may have less capacity for emotion regulation duties. Furthermore, the experience of high temperature itself, is likely to be encoded as a stressor/threat with a direct line to our autonomic nervous system that governs the stress response. If you add to that the impact of the temperature to sleeping (which the hypothalamus also has a role in regulating) you start to get an understanding of just how much is going on the surface to keep us at some sort of an equilibrium. A moment of appreciation for the hypothalamus please?
All of the above is just at a physiologic level. If we add to that our psychological experience of being aware that we feel less able to get things done, worrying about it, feeling frustrated, etc., etc., we can see how layers are quickly added to our experience, making there even more for the brain to regulate!
What you can do to look after your brain and body in the heat?
Hopefully this article has given you an appreciation of how hard your body is working for you in the heat. You can return the favour by helping your body out doing the following:
· Keep hydrated! Think nice ice cold water for a special treat to your hypothalamus, so It’s got lots to send to the surface of your skin
· If you have a fan, use it! If you don’t consider getting one (it doesn’t have to be expensive). Putting a fan over an ice bowel of water can reduce your temperature further and feel heavenly.
· Consciously think about how you can help cool your body down. Keep curtains shut during the day if you’re not in rooms. Plan activities that aren’t going to add too much of a burden in the heat and if they are make sure you can balance it out. E.g. if you want to run, do it prior to 9am or after 8pm. If you are
· Don’t expect the same level of functionality from yourself. It is not reasonable, attainable and it will only make you feel more frustrated.
· Take mini moments to check in. As we’ve seen, your hypothalamus is working hard for you. It would appreciate any added support you can give it in calming down your emotional temperature. This doesn’t have to be extensive. Every 2-3 hours, take a moment to notice how you feel. How would you describe your mood? The regularity helps prevent cumulative build up of stress. If you notice hot emotions building, start to intervene. Give yourself a break. Jot down thoughts. Take some breaths. Look out of the window. These small things added up can make a great difference to your day.
As you come to the end of this article, ask yourself what stood out? Is this something that other people you know would benefit from knowing too? Sharing is a powerfully connecting action and human connection, is more tonic for our emotion regulation pathways.
Keep cool and have a lovely day
References
[1] Laurent, J. G. C., Williams, A., Oulhote, Y., Zanobetti, A., Allen, J. G., & Spengler, J. D. (2018). Reduced cognitive function during a heat wave among residents of non-air-conditioned buildings: An observational study of young adults in the summer of 2016. PLoS medicine, 15(7), e1002605.
[2] Rastegar, Z., Ravandi, M. R. G., Zare, S., Khanjani, N., & Esmaeili, R. (2022). Evaluating the effect of heat stress on cognitive performance of petrochemical workers: A field study. Heliyon, 8(1), e08698.
[3] Barbosa Escobar, F., Velasco, C., Motoki, K., Byrne, D. V., & Wang, Q. J. (2021). The temperature of emotions. PloS one, 16(6), e0252408.
[4] Noelke, C., McGovern, M., Corsi, D. J., Jimenez, M. P., Stern, A., Wing, I. S., & Berkman, L. (2016). Increasing ambient temperature reduces emotional well-being. Environmental research, 151, 124-129
[5] Baryshnikova, N., Davidson, S., & Wesselbaum, D. (2022). Do you feel the heat around the corner? The effect of weather on crime. Empirical Economics, 63(1), 179-199
[6] Basu, R., Gavin, L., Pearson, D., Ebisu, K., & Malig, B. (2018). Examining the association between apparent temperature and mental health-related emergency room visits in California. American journal of epidemiology, 187(4), 726-735.
[7] Wang, X., Lavigne, E., Ouellette-kuntz, H., & Chen, B. E. (2014). Acute impacts of extreme temperature exposure on emergency room admissions related to mental and behavior disorders in Toronto, Canada. Journal of affective disorders, 155, 154-161.
[8] Lee, W., Moon, M., Kim, H. G., Lee, T. H., & Oh, M. S. (2015). Heat stress-induced memory impairment is associated with neuroinflammation in mice. Journal of neuroinflammation, 12(1), 1-13.
Many studies have explored the impact of heat on cognitive function in the workplace and education. Consistently it is found that people in the high heat experimental conditions have longer reaction times and increased rates of errors compared to their air-conditioned counterparts. [1],[2] Research exploring the relationship between temperature and emotions is more limited, however there tends to a trend towards higher temperatures and negative emotional experiences.[3] Self-reports of stress and anger increase and there is an increase in aggression.[4],[5] Indeed, studies in the US[6] and Canada[7] have demonstrated on days with hotter weather there are increased emergency room admissions for mental health presentations.
So why do we feel so impacted by the heat?
The answer lies in our central nervous system and a particular region of the brain called the hypothalamus. Our body temperature is regulated by the hypothalamus, which coordinates consequent action across the central nervous system. Here’s for some quick science:
We have thermoreceptors in our skin that detect change in the air temperature around us. When temperature rises or falls past levels we are used to, this triggers a thermoregulatory response. What this response will be, depends on the direction of change in temperature and to what degree. The hypothalamus is constantly balancing external temperature with internal core body temperature. When temperature rises, our hypothalamus can orchestrate bodily temperature regulation by two pathways: (1) physiological thermoregulation which involves things like shivering, skin blood flow and water evaporation (i.e. sweating) and (2) behavioural thermoregulation which may involve us changing our posture, seeking out different environments, or altering our current environment (e.g. looking for shade).
When the hypothalamus determines we need cooling down, it signals for blood vessels to dilate, sending warm blood to the surface of the skin (along with fluids and salts) to allow them to evaporate. We experience this as sweating. Heatstroke occurs when there is nothing left to evaporate and can have severe consequences, even resulting in the death of cells in the brain if we don’t cool and rehydrate. Mice studies have demonstrated that heat stress can lead to inflammation in the hippocampus (area of our brain associated with memory), which authors hypothesise could be a causative factor for memory loss, and neuronal death.[8]
Appreciating the substantial coordination of heat regulation within the brain, can help us to also understand how we then come to feel emotionally impacted. Some key things to note are that structures involved in temperature regulation, are also structures involved in emotion regulation. You may have heard of the fight/flight/freeze response. That whole response essentially originates in the hypothalamus. As the hypothalamus is taxed with temperature regulation duties, it may have less capacity for emotion regulation duties. Furthermore, the experience of high temperature itself, is likely to be encoded as a stressor/threat with a direct line to our autonomic nervous system that governs the stress response. If you add to that the impact of the temperature to sleeping (which the hypothalamus also has a role in regulating) you start to get an understanding of just how much is going on the surface to keep us at some sort of an equilibrium. A moment of appreciation for the hypothalamus please?
All of the above is just at a physiologic level. If we add to that our psychological experience of being aware that we feel less able to get things done, worrying about it, feeling frustrated, etc., etc., we can see how layers are quickly added to our experience, making there even more for the brain to regulate!
What you can do to look after your brain and body in the heat?
Hopefully this article has given you an appreciation of how hard your body is working for you in the heat. You can return the favour by helping your body out doing the following:
· Keep hydrated! Think nice ice cold water for a special treat to your hypothalamus, so It’s got lots to send to the surface of your skin
· If you have a fan, use it! If you don’t consider getting one (it doesn’t have to be expensive). Putting a fan over an ice bowel of water can reduce your temperature further and feel heavenly.
· Consciously think about how you can help cool your body down. Keep curtains shut during the day if you’re not in rooms. Plan activities that aren’t going to add too much of a burden in the heat and if they are make sure you can balance it out. E.g. if you want to run, do it prior to 9am or after 8pm. If you are
· Don’t expect the same level of functionality from yourself. It is not reasonable, attainable and it will only make you feel more frustrated.
· Take mini moments to check in. As we’ve seen, your hypothalamus is working hard for you. It would appreciate any added support you can give it in calming down your emotional temperature. This doesn’t have to be extensive. Every 2-3 hours, take a moment to notice how you feel. How would you describe your mood? The regularity helps prevent cumulative build up of stress. If you notice hot emotions building, start to intervene. Give yourself a break. Jot down thoughts. Take some breaths. Look out of the window. These small things added up can make a great difference to your day.
As you come to the end of this article, ask yourself what stood out? Is this something that other people you know would benefit from knowing too? Sharing is a powerfully connecting action and human connection, is more tonic for our emotion regulation pathways.
Keep cool and have a lovely day
[1] Laurent, J. G. C., Williams, A., Oulhote, Y., Zanobetti, A., Allen, J. G., & Spengler, J. D. (2018). Reduced cognitive function during a heat wave among residents of non-air-conditioned buildings: An observational study of young adults in the summer of 2016. PLoS medicine, 15(7), e1002605.
[2] Rastegar, Z., Ravandi, M. R. G., Zare, S., Khanjani, N., & Esmaeili, R. (2022). Evaluating the effect of heat stress on cognitive performance of petrochemical workers: A field study. Heliyon, 8(1), e08698.
[3] Barbosa Escobar, F., Velasco, C., Motoki, K., Byrne, D. V., & Wang, Q. J. (2021). The temperature of emotions. PloS one, 16(6), e0252408.
[4] Noelke, C., McGovern, M., Corsi, D. J., Jimenez, M. P., Stern, A., Wing, I. S., & Berkman, L. (2016). Increasing ambient temperature reduces emotional well-being. Environmental research, 151, 124-129
[5] Baryshnikova, N., Davidson, S., & Wesselbaum, D. (2022). Do you feel the heat around the corner? The effect of weather on crime. Empirical Economics, 63(1), 179-199
[6] Basu, R., Gavin, L., Pearson, D., Ebisu, K., & Malig, B. (2018). Examining the association between apparent temperature and mental health-related emergency room visits in California. American journal of epidemiology, 187(4), 726-735.
[7] Wang, X., Lavigne, E., Ouellette-kuntz, H., & Chen, B. E. (2014). Acute impacts of extreme temperature exposure on emergency room admissions related to mental and behavior disorders in Toronto, Canada. Journal of affective disorders, 155, 154-161.
[8] Lee, W., Moon, M., Kim, H. G., Lee, T. H., & Oh, M. S. (2015). Heat stress-induced memory impairment is associated with neuroinflammation in mice. Journal of neuroinflammation, 12(1), 1-13.
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