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Healthy Environments
for Learning Day (HELD) is Thursday April 24, 2025
Extreme Heat in Schools and Child Care Settings.
Why is Extreme Heat a concern?
Extreme heat poses significant health risks, especially for young children, who are particularly vulnerable to heat-related illnesses. Extreme heat not only affects children’s health but also their wellbeing, hindering their ability to learn and thrive in educational settings.
Extreme heat is a serious health risk for everyone – and especially dangerous for children.1 Children’s bodies have limited ability to acclimatize to heat, their higher metabolism increases the risk of dehydration, and their sweating rates are lower than adults which may limit their ability to cool down. Children also tend to be more physically active, which generates body heat that further increases their health risk on hot days.2 3 4 Young children are dependent on adults for protection from the heat, and they may not be able to express their feelings of overheating.5 6
Physical health impacts of extreme heat in children include heat stroke, heat exhaustion, heat rash, heat cramps and swelling of hands, feet and ankles.7 Children most at risk of heat-related illnesses include those with breathing difficulties (asthma), heart conditions, kidney problems, mental and physical disabilities, developmental disorders, diarrhea, and those who take certain medications. 8 9 There is some evidence to suggest that prolonged exposure to extreme heat can also negatively affect children’s immune function and increase susceptibility to infection.10
Extreme heat also affects children’s brain health and learning. Elevated temperatures can reduce children’s ability to concentrate in school, affecting student performance. Heat’s effects on the brain can produce slower reaction times and an inability to focus.11 12 Disruption in sleep due to heat can lead to learning difficulties and emotional and behavioural challenges in children.13 Warm days, and in particular hot days, have been associated with increased school absences.14
Extreme heat amplifies health inequities for children. Children living in socio-economically marginalized communities are at greater risk of excessive heat – often having less access to cooling methods such as air-conditioned homes and schools, and lower availability of green spaces.15
1 Health Canada. 2024. Keep Children Cool! Protect Your Child from Extreme Heat. [website accessed March 18, 2024] https://www.canada.ca/en/health-canada/services/publications/healthy-living/keep-children-cool-extreme-heat.html
2 Health Canada. 2011. Communicating the Health Risks of Extreme Heat Events: Toolkit for Public Health and Emergency Management Officials. https://www.canada.ca/content/dam/hc-sc/migration/hc-sc/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/climat/heat-chaleur/heat-chaleur-eng.pdf
3 Falk B, Dotan R. Children’s thermoregulation during exercise in the heat: a revisit. Appl Physiol Nutr Metab. 2008 Apr;33(2):420-7. doi: 10.1139/H07-185. PMID: 18347699. https://pubmed.ncbi.nlm.nih.gov/18347699/
4 Gosselin, P., Campagna, C., Demers-Bouffard, D., Qutob, S., & Flannigan, M. (2022). Natural Hazards. In P. Berry & R. Schnitter (Eds.), Health of Canadians in a Changing Climate: Advancing our Knowledge for Action. Ottawa, ON: Government of Canada. https://changingclimate.ca/health-in-a-changing-climate/chapter/3-0/
5 Falk B, Dotan R. Children’s thermoregulation during exercise in the heat: a revisit. Appl Physiol Nutr Metab. 2008 Apr;33(2):420-7. doi: 10.1139/H07-185. PMID: 18347699. https://pubmed.ncbi.nlm.nih.gov/18347699/
6 M.A. Folkerts, N. Gerrett, B.R.M. Kingma, M. Zuurbier, H.A.M. Daanen, Care provider assessment of thermal state of children in day-care centers, Building and Environment, Volume 179, 2020, 106915, ISSN 0360-1323, https://doi.org/10.1016/j.buildenv.2020.106915. (https://www.sciencedirect.com/science/article/pii/S0360132320302742)
7 Health Canada. 2024. Keep Children Cool! Protect Your Child from Extreme Heat. [website accessed March 18, 2024] https://www.canada.ca/en/health-canada/services/publications/healthy-living/keep-children-cool-extreme-heat.html
8 Health Canada. 2024. Keep Children Cool! Protect Your Child from Extreme Heat. [website accessed Mrch 18, 2024] https://www.canada.ca/en/health-canada/services/publications/healthy-living/keep-children-cool-extreme-heat.html
9 Xu, Z., Sheffield, P.E., Su, H. et al. The impact of heat waves on children’s health: a systematic review. Int J Biometeorol 58, 239–247 (2014). https://doi.org/10.1007/s00484-013-0655-x
10 Early Childhood Scientific Council on Equity and the Environment. (2023). Extreme Heat Affects Early Childhood Development and Health: Working Paper No. 1. Retrieved from www.developingchild.harvard.edu https://developingchild.harvard.edu/wp-content/uploads/2024/10/ECSCEE-Heat-Paper.pdf
11 M.A. Folkerts, N. Gerrett, B.R.M. Kingma, M. Zuurbier, H.A.M. Daanen, Care provider assessment of thermal state of children in day-care centers, Building and Environment, Volume 179, 2020, 106915, ISSN 0360-1323, https://doi.org/10.1016/j.buildenv.2020.106915. (https://www.sciencedirect.com/science/article/pii/S0360132320302742)
12 Early Childhood Scientific Council on Equity and the Environment. (2023). Extreme Heat Affects Early Childhood Development and Health: Working Paper No. 1. Retrieved from www.developingchild.harvard.edu https://developingchild.harvard.edu/wp-content/uploads/2024/10/ECSCEE-Heat-Paper.pdf
13 M.A. Folkerts, N. Gerrett, B.R.M. Kingma, M. Zuurbier, H.A.M. Daanen, Care provider assessment of thermal state of children in day-care centers, Building and Environment, Volume 179, 2020, 106915, ISSN 0360-1323, https://doi.org/10.1016/j.buildenv.2020.106915. (https://www.sciencedirect.com/science/article/pii/S0360132320302742)
14Conte Keivabu, R. Temperature and school absences: evidence from England. Popul Environ 46, 6 (2024). https://doi.org/10.1007/s11111-024-00448-5
15 Early Childhood Scientific Council on Equity and the Environment. (2023). Extreme Heat Affects Early Childhood Development and Health: Working Paper No. 1. Retrieved from www.developingchild.harvard.edu https://developingchild.harvard.edu/wp-content/uploads/2024/10/ECSCEE-Heat-Paper.pdf
What change is needed?
In Canada, many schools and child care settings are ill-equipped to protect children and staff during extreme heat events. Due to climate change, extreme heat events in Canada are increasing in severity, frequency and duration.1
Communities all across Canada are seeing an increase in the number of extreme heat events.2 The number of days above 30oC is expected to double or triple in some parts of Canada in the near term (2021 – 2050) because of climate change .3 4 5 Children typically spend at least 6-8 hours a day in schools or child care settings, and without adequate cooling mechanisms, temperatures within these settings can exceed safe levels during extreme heat events. With heat waves getting hotter, longer and more common, urgent action is needed to protect children and staff from this escalating health risk.
Options exist to optimize learning settings to protect against extreme heat. Extreme heat affects children both indoors and outdoors. Actions to maintain healthy indoor temperatures can include heat mitigation measures such as window coverings to block incoming solar radiation, investing in building retrofits and upgrading mechanical cooling.6 7 In outdoor settings, utilizing seasonal shade, light-coloured pervious surfaces and increasing tree canopy coverage all help to lower air and surface temperatures.8 9 Optimizing learning settings with heat protective measures provides an opportunity for these environments to be a place of respite from extreme heat that may otherwise be faced at home or in communities.
Learn more about the actions to protect children’s health during extreme heat:
Learn more about outdoor settings, including shade coverage, tree canopy, urban heat islands and thermally comfortable playgrounds:
Learn more about indoor settings, including the benefits of building retrofits, active mechanical cooling systems and the building envelope:
Additional resources on extreme heat and the health impacts of climate change:
- Extreme Heat Events
- Extreme Heat Guide
- HealthyPlan.City Heat Mapping Tool
- Health of Canadians in a Changing Climate
- Climate Change and Indigenous Peoples’ Health in Canada
- Using Foresight to Contemplate the Future of Early Childhood in Canada
- The Health Costs of Climate Change: How Canada Can Adapt, Prepare and Save Lives
1 Gosselin, P., Campagna, C., Demers-Bouffard, D., Qutob, S., & Flannigan, M. (2022). Natural Hazards. In P. Berry & R. Schnitter (Eds.), Health of Canadians in a Changing Climate: Advancing our Knowledge for Action. Ottawa, ON: Government of Canada.
https://changingclimate.ca/health-in-a-changing-climate/chapter/3-0/
2 Government of Canada. Extreme heat events. [accessed March 25, 2025]. https://www.canada.ca/en/environment-climate-change/services/environmental-indicators/extreme-heat-events.html
3 Climate Atlas of Canada. Very Hot Days (=30C), 2021-2050 [accessed March 20, 2025] https://climateatlas.ca/map/canada/plus30_2030_85#
4 Canadian Association of Physicians for the Environment (CAPE). Climate Change Toolkit for Health Professionals: Module 3 – Climate Change Health Impacts across Canada. April 2019. Author: Helen Doyle. Editor: Kim Perrotta. https://cape.ca/wp-content/uploads/2019/05/Climate-Change-Toolkit-for-Health-Professionals-Updated-April-2019-2.pdf
5 ClimateData.ca. Map of the Month: Days Above 30C. April 2024. Ryan Smith, Canadian Centre for Climate Services. https://climatedata.ca/map-of-the-month-days-above-30c/
6 Canadian Public Health Association. (2021). Building Retrofits Factsheet: Invest in building retrofits for healthy, green and just communities. https://www.cpha.ca/building-retrofits-factsheet
7 Akkose, G., Akgul, C. M., Dino, I. G. (2021). Educational building retrofit under climate change and urban heat island effect. Journal of Building Engineering, ISSN: 2352-7102, Vol: 40, Page: 102294. https://doi.org/10.1016/j.jobe.2021.102294
8 Yin, Y., Li, S., Xing, X., Zhou, X., Kang, Y., Hu, Q., & Li, Y. (2024). Cooling Benefits of Urban Tree Canopy: A Systematic Review. Sustainability, 16(12), 4955. https://doi.org/10.3390/su16124955
9 Health Canada. (2020). Reducing urban heat islands to protect health in Canada: An introduction for public health professionals. Ottawa: Health Canada. https://www.canada.ca/en/services/health/publications/healthy-living/reducing-urban-heat-islands-protect-health-canada.html
It's time to take action!
CPCHE is mobilizing partners and collaborators through the 2025 Healthy Environments for Learning Day (HELD) campaign to call upon decision makers to take urgent action on extreme heat in schools and child care settings across Canada. Join us in collectively advocating for action to protect children and staff from the dangers of extreme heat. All children have the right to learn in environments that promote their health and well-being.
HELD 2025 Extreme Heat Collective Call for Action
healthyenvironmentforkids.ca/held/2025-campaign-call-for-action/
Campaign Resources
Funders
CPCHE gratefully acknowledges the support provided for the 2025 Healthy Environments for Learning Day campaign by:
