Effect of Heat on Outdoor Recess in Arizona Elementary Schools, July–September 2023

Abstract

School recess is an important setting to support children’s health; however, inclement weather, including extreme heat, affects the provision of recess. We conducted a cross-sectional study to determine the number of days that recess in elementary schools was disrupted because of heat in the first quarter of the 2023-2024 school year. We obtained data by conducting a survey among teachers representing 61 elementary schools in Maricopa County, Arizona. Daily high temperatures during this time ranged from 90°F (32.2°C) to 119°F (48.3°C). Almost all schools (93%) modified traditional outdoor recess because of heat. Across schools, recess disruption averaged 3.5 weeks. Almost half of the schools (49%) reported 4 to 6 weeks of disrupted recess, comprising 44% to 67% of the first quarter of the school year or up to 16% of the entire school year. Although state policies mandating daily school recess exist, they generally do not address the provision of recess during inclement weather, including heat. Given the health benefits of recess for children, minimizing heat exposure in schoolyards and supporting indoor recess during times of extreme heat should be prioritized.

Although relative to the local context, extreme heat is generally considered as periods of at least 2 days when the heat index, or a combination of heat and humidity, exceeds 105°F to 110°F. ¹ Extreme heat has led to school closures in the United States and throughout the world. Many of these closures resulted from infrastructure challenges inside school buildings, such as classrooms becoming too hot because of inadequate air conditioning. If temperatures rise as predicted, ² heat-related school closures will likely increase; yet, even when schools do not officially close, heat disrupts many components of the school day, which can affect children’s health and learning. In particular, the inability for children to safely spend time outdoors at school because of extreme heat is a public health concern.

Extreme heat affects multiple aspects of the school day that traditionally occur outside, such as the ability to travel safely if walking or biking to or from school or bus stops. Lack of safe and reliable transportation is linked to chronic absenteeism, a key predictor of academic success and likelihood of graduating. ³ High temperatures increase the risk of heat illness for youth athletes ⁴ and negatively affect learning and enjoyment in physical education. ⁵ Of great concern, however, are disruptions to school recess.

Recess often provides the only break from academic instruction, allowing children time for unstructured play that fosters social and emotional health and development. ⁶ Without recess, children’s opportunities for physical activity at school are limited, contributing to increased sedentary time. ⁷ Beyond health, recess positively affects academic performance, as breaks during the school day have been shown to improve attention, behavior, and cognitive development. ⁸ Most US schools (82.8%) report having daily school recess ⁹ ; however, the extent to which heat affects recess, which may have consequences for children’s health and well-being, is not fully understood. To address this gap in knowledge, we assessed the number of school days during the first quarter (semester) of the 2023-2024 school year that outdoor recess was disrupted because of heat in Maricopa County, the hottest and most populous county in Arizona. Across Arizona, similar to that shown in many other states, no universal guidance or temperature threshold has been provided to schools to determine recess cancellation during times of extreme heat. Because the decision of how to manage recess is left to individual schools or school districts, recess practices during extreme heat differ. Thus, we also explored variations in the number of recess disruptions among school districts.

Methods

Design and Setting

For this cross-sectional study, we used data from a survey administered online to elementary school teachers in Maricopa County in October 2023. We aligned survey questions with a model developed by the Arizona Department of Health Services to represent methods that schools can use to mitigate the effects of environmental heat for children. ⁴ Maricopa County, where 63% of the state population resides, ¹⁰ experiences consistently high temperatures of more than 100°F (38°C) during the fall school semester or first 3 months of the school year (July, August, September). ¹¹ In 2023, daily high temperatures during this period ranged from 90°F (32.2°C) to 119°F (48.3°C). ¹² For the survey, we included teachers who taught at an elementary school or at a kindergarten through grade 8 or kindergarten through grade 12 school. The Arizona State University Institutional Review Board (STUDY00014478; September 22, 2023) approved our study, and participants provided written consent before starting the survey.

Recruitment and Procedures

We sent survey invitations by email to all physical education teachers by using lists provided by the state department of education and the state professional physical education organization. We asked participants to complete the survey only once if they received 2 invitations. Participants had the option to enter a raffle to win 1 of 15 $25 electronic gift cards. We administered the survey online by using the Research Electronic Data Capture (REDCap) platform. We included questions to assess the following: whether traditional outdoor recess had been modified because of heat; the number of school days recess was modified during the past 3 months (ie, “heat days”), which comprised the typical first quarter of the academic year (or about 45 school days) from the start of the school year in July through September; and which of 8 possible modifications from an existing tool ¹³ were used. Possible modifications included whether recess was shortened, made optional, limited to shaded areas, shifted to earlier times, moved indoors to gymnasiums, moved indoors to classrooms, added to lunch time, and/or canceled completely.

Data Analysis

We calculated central tendency measures to determine the average number of heat days and percentage of participants who reported modifications to outdoor recess because of heat and descriptive statistics to summarize the number of heat days by school district. We calculated the intracluster coefficient, which represented the proportion of variance in heat days accounted for by differences at the district level. We used SPSS version 28.0.1.1(15) (IBM) for all analyses.

Results

Participants representing 61 elementary schools across Maricopa County responded to the survey (15% response rate, representing 11% of county elementary schools). At almost all schools (n = 57; 93%), traditional outdoor recess was reportedly modified because of heat. Across participating schools that reported modifications, on average, recess was modified for 17 of the 45 school days or more than 3 school weeks. Four schools did not provide the number of days modified. Among the 53 schools that reported number of days modified, 26 (49%) indicated that recess was modified for 4 weeks or more and 14 (26%) reported 6 weeks of modified recess, equivalent to 67% of the first quarter of the school year. Schools reported moving recess indoors or canceling recess as the most frequent type of modifications used on hot days (59%); among modifications used to continue recess outdoors (41%), the most common changes included shortening recess, moving recess times earlier in the day, and limiting activity to shaded areas. Responses were clustered among 25 school districts (Table). Clusters ranged from 1 to 7 schools within a district. The intracluster coefficient for heat days was 0.39, indicating that 39% of the variance was attributed to differences at the district level; however, the number of reported days of recess disruption ranged from 0 to 23 days among schools in the same district.

Table.

Number of days that elementary school recess was interrupted because of heat in Maricopa County, Arizona, during the first quarter of the 2023-2024 school year, by school district ^a

School district (N = 25) b	No. of participating schools that modify recess due to heat (N = 53) c	No. of days of disrupted recess
		Mean (SD)	Range
A	7	22.7 (4.8)	17-28
B	6	15.8 (9.1)	6-27
C	4	19.3 (6.4)	14-28
D	4	20.3 (5.6)	15-28
E	4	8.8 (2.5)	5-10
F	3	10.7 (1.2)	10-12
G	3	28.0 (0.0)	—
H	2	16.5 (16.3)	5-28
I	2	17.5 (10.6)	10-25
J	2	24.0 (5.7)	20-28
K	2	5.0 (0.0)	—
L	1	28.0 (—)	—
M	1	27.0 (—)	—
N	1	20.0 (—)	—
O	1	20.0 (—)	—
P	1	16.0 (—)	—
Q	1	15.0 (—)	—
R	1	15.0 (—)	—
S	1	15.0 (—)	—
T	1	12.0 (—)	—
U	1	7.0 (—)	—
V	1	7.0 (—)	—
W	1	5.0 (—)	—
X	1	5.0 (—)	—
Y	1	3.0 (—)	—
Total	53	16.7 (8.3)	3-28

Abbreviation: —, not applicable.

^aData on number of days of disrupted recess were obtained from a survey administered online to elementary school teachers in Maricopa County in October 2023.

^bLetters represent pseudonyms to keep school names anonymous.

^cFour schools did not report how many days were modified due to heat.

Discussion

During the first quarter of the school year, 93% of Maricopa County schools that participated in our survey indicated some recess disruption, with almost half reporting disruption 44% to 67% of the time because of heat days. Variations in disruptions occurred among school districts and even among schools in the same school district. Although daily high temperatures did vary by 19°F (16.1°C) across the study period, variations in temperatures between school locations were not more than a few degrees, ¹¹ yet most schools in the same school district reported considerable variations in the number of recess disruptions. Data are scarce on who makes decisions and what information is used to inform decision-making with regard to recess in US schools during extreme heat. In addition, although some guidance about the safety of outdoor activity in different heat conditions exists, ⁴ no current policies are in place to support informed decision-making about how to modify outdoor recess or to support indoor recess. This gap in policy is particularly concerning because daily recess is mandated by many state policies across the United States, including ARS§15-118 in Arizona. ¹⁴

Efforts to address inadequate air conditioning in US schools are projected to cost more than $100 billion by 2040 ¹⁵ ; however, the issue of extreme heat extends beyond sufficient indoor cooling systems, because many schools do not have the space or resources to offer quality recess indoors. Solutions to lessening disruptions to outdoor school recess will require a broader set of interventions that consider outdoor environments that emphasize passive cooling, such as shaded play areas and heat-mitigating infrastructure (eg, green infrastructure). ⁴ In scenarios in which outdoor recess is canceled, adequate indoor facilities and resources, such as supervision and equipment to support children’s movement and socialization through play, should be prioritized.

Public Health Implications

Children will experience many more abnormally hot days during their lifetimes compared with their grandparents’ generation. ¹⁶ In the year since we administered this survey, Arizona experienced another record-setting hot start to the 2024-2025 school year, including the latest annual 110°F+ (43°C) daily high ever recorded on October 7, 2024. Rising temperatures are projected for all parts of the United States during the next several decades. ² Considering the crucial social, emotional, and physical health benefits of recess for children, ensuring that opportunities for quality recess can persist despite increasingly high and prolonged heat is a growing public health concern.