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Dangers of Hot Vehicles and Children – Transport Canada’s Initiatives to Countering Pediatric Vehicular Heatstroke

Hours Posted on Hours Updated on

By:

Caroll Lau, B.Sc., M.Sc.  Human Factors Specialist, Transport Canada
Patrick Kehoe, B.Eng., M.A.Sc. – Senior Researcher, National Research Council Canada
Zuzanna Strom, B.A., M.a. – Manager, Consumer Awareness and Road Users, Transport Canada

Abstract:

Pediatric Vehicular Heatstroke (PVH) is a life-threatening condition that occurs when a child is left in a hot vehicle, leading to rapid and dangerous increases in body temperature. This paper explores the causes and prevalence of PVH, common misconceptions, and highlights preventive strategies. It examines Transport Canada's initiatives, including awareness campaigns, stakeholder engagement, a survey to understand caregiver safety perceptions and awareness about PVH, and research involving the evaluation of technological countermeasures like occupant monitoring systems. Despite these efforts, further research and policies are needed to close knowledge gaps and enhance prevention. The goal is to protect children from PVH and eliminate these preventable tragedies through awareness and innovation.

Background on Pediatric Vehicular Heatstroke
What is PVH?
Pediatric vehicular heatstroke (PVH) occurs when a child is left alone in a vehicle and their body temperature exceeds safe levels (a core body temperature greater than 40 degrees Celsius). This can lead to heat-related illnesses or injuries, such as brain damage, coma, or possibly death. Children are particularly vulnerable to heatstroke because their bodies are unable to thermoregulate as efficiently as adults. According to the American Pediatrics Society, a child's body temperature heats up about 3 to 5 times faster than an adult’s (18).

Studies show that temperatures inside parked vehicles can rise rapidly, even on mild days, and most of the rise in temperature inside the vehicle occurs within the first 15 to 30 minutes (1, 2). Even pre-cooling a vehicle with the air conditioner prior to leaving it off has been shown to have negligible effects. A study showed that 5 minutes after turning off the air conditioner, the vehicle reached ambient temperatures and then continued to heat up at a similar rate as instances without prior air conditioning (2).

Another misconception is that leaving the vehicle’s windows cracked open is sufficient to keep the interior of a vehicle cool. However, studies show that “cracked” windows do not make a significant impact on slowing down the heating of the vehicle nor lowering the interior temperature (2, 3).

Incidence and circumstances contributing to PVH deaths

Currently, there is no official Canada-wide system to gather incidence of PVH deaths, injuries, or close-calls, nor to gather information on the circumstances contributing to PVH. Different jurisdictions monitor these cases to a varying extent. However, a 2019 study that reviewed Canadian PVH cases between 2013-2018 found that an average of one PVH death occurs in Canada per year (4). For comparison, 37 deaths occur in the United States (U.S.) annually, with a total of 971 deaths since 1998 (5).

Although Canadian data are limited with respect to incidence U.S. organizations, such as noheatstroke.org and kidsandcars.org, explain that more than half (>50%) of PVH deaths occur after a parent or caregiver forgets a child in a vehicle, about a quarter of deaths (25%) happen when an unsupervised child accesses an unlocked vehicle and gets stuck inside, and about one fifth (20%) of deaths happen when a child is intentionally left alone in a vehicle (Figure 1) (5).

Figure 1. Most common circumstances that lead to PVH related fatalities based on findings from http://noheatstroke.org (5)

U.S. cases show that children most at risk of dying in a hot vehicle are 3 years and younger, and the responsible person(s) for PVH deaths is usually the child’s parent (5).

A closer look at the largest cause of PVH deaths: the child is forgotten in a vehicle

Many preventable deaths and injuries occur in our society despite people knowing the risks involved with impaired driving, speeding, or not wearing their seatbelt, but many parents and caregivers are not aware of the risks associated with leaving a child in a vehicle.

Experts indicate that forgetting a child in a vehicle can happen to anyone and that it does not necessarily indicate intentionally reckless or negligent behaviour from caregivers. In fact, many responsible and loving parents have experienced PVH tragedies. Dr. David Diamond, Neurobehavioural Scientist and Professor of Psychology at the University of South Florida has studied PVH and served as an expert witness in numerous cases on this topic and explains that various factors contribute to this phenomenon. These include the loss of awareness that the child is in the vehicle (e.g., the child fell asleep), a failure in the driver’s prospective memory, which involves remembering to perform an intended action in the future, and different stressors and distractions that contribute to the failure of this prospective memory (6 - 8).

In a recent American study on the risk perception and attitudes of caregivers toward PVH, 1,500 caregivers were asked whether they perceived a risk that they could accidentally leave a child alone in a vehicle in the next month. Only a small proportion (6%) believed that it was somewhat or very likely to occur (9). These results are consistent with Dr. Diamond’s assessment that “most people refuse to take any precautionary measures because they believe this could never happen to them, a potentially fatal mistake” (6).

Tips and strategies to prevent PVH

In general, the following guidance is offered by PVH advocates to parents and caregivers to prevent PVH (4, 5, 10, 11):

  • Never leave a child alone in a vehicle
  • Lock parked vehicles to prevent children from accessing a vehicle without supervision
  • Keep vehicle keys away from children’s reach to prevent them from accessing a vehicle unattended
  • Take extra caution when changing routines or schedules including holidays, and during busy times, such as the morning rush
  • Be extra vigilant when you are tired or stressed
  • Reduce the likelihood of distractions while driving and when getting in and out of the vehicle
  • Create precautionary habits:
    • check the rear seat before leaving the vehicle
    • engage with your child during the vehicle ride, whether the child is asleep or not
    • place items you will need such as phone or purse in the back seat
    • teach children how to honk the horn and how to exit the car in the event they are trapped inside
  • Create reminders:
    • Place the child’s backpack or diaper bag in the front seat to serve as a visual reminder
    • Place an extra mirror to see the child in the rear seat
    • Ask the childcare provider to notify you if the child does not arrive at the planned destination

Transport Canada’s efforts in preventing PVH deaths in Canada

TC works to prevent PVH in three main ways: 1) Awareness campaigns; 2) Engagement with stakeholders; and 3) Research initiatives and collaborative projects.

1) Awareness campaigns

TC’s PVH safety campaigns aim to generate awareness among Canadian parents, caregivers, and the public about the importance of not leaving a child alone in a vehicle. These campaigns leverage multiple tools including social media, advertisements, websites, and videos. These campaigns typically run during warmer months, from May to September, to coincide with hotter temperatures and provide messaging during back-to-school season, when routines tend to change for many families in Canada.

TC’s most recent advertising PVH campaign reached over 10 million viewers between the ages of 18-65 over a span of 8 days. The messaging was focused on two important aspects: 1) to educate parents and caregivers why it’s important not to leave a child alone in a hot vehicle, and 2) to educate bystanders what to do should they encounter a child left alone in a vehicle. While parents of children of all ages only accounted for 34.35% of all campaign impressions, this group accounted for half of all link clicks redirecting them to TC’s website on PVH. This demonstrated that parents held an interest in learning more about the subject matter.

Considering videos serve as an effective and engaging medium for communicating messaging, TC created a video demonstrating the warming effects inside a vehicle and how this can pose a danger to children. Following a preliminary scan of videos on this topic from around the world, TC applied an engineer-based concept featuring two TC investigators with a crash test dummy in a child restraint in a SUV. The vehicle was equipped with various temperature sensors explaining how quickly a parked vehicle can warm up.

The public can access this video as well as more information on the dangers of PVH and strategies on how to mitigate those risks by visiting TC’s Dangers of Hot Vehicles and Children website. The website also includes information on vehicle technologies, such as rear occupant alert systems currently available on the market aimed to help mitigate PVH risks. The purpose is to help inform consumers about these technologies, their capabilities, and note their limitations to prevent over-reliance on these systems. More information about these systems is available on TC’s driver assistance technologies webpages accessible at: Driver Assistance Technologies.

2) Engagement with stakeholders

Noting the complexity of PVH, TC engages with relevant stakeholders to profile the importance of addressing PVH and assess effective mitigation strategies. This includes regular engagement with vehicle and juvenile product manufacturers to learn about new technologies and countermeasures emerging on the market to address PVH risks. TC also engage with other federal and provincial government departments, child car seat technicians, child safety advocates, road safety associations, and international counterparts, including the U.S. Department of Transport National Highway Traffic Safety Administration (NHTSA), which has had a substantive safety campaign on this topic for many years.

As part of its efforts, TC participates in the U.S. National Safety Council PVH Stakeholder Workgroup, which works to study and develop countermeasures to prevent child hot car injuries and deaths. Internationally, TC sits on the UNECE World Forum for Harmonization of Vehicle Regulations (WP.29) Informal Working Group on PVH which aims to assess vehicle technology capabilities to mitigate PVH risks.

3) Research Initiatives and Collaborative Projects

Preliminary findings on Participants’ Safety Perceptions and Opinions of Pediatric Vehicular Heatstroke

In February 2024, Transport Canada participated in the Canada Science and Technology Museum’s Science Fair. Questionnaires about caregivers’ attitudes and perceptions about PVH were administered through a one-on-one semi-structure interview. Please note that the following data have not been published and may be a pilot to a bigger study in the future. A total of 18 responses were collected, 14 of which were participants who had children under the age of 8 and the remaining four reported not having any children or any childcare responsibilities. Parents with children all reported having a vehicle for transportation and of the 14, eight reported having left their children alone in a vehicle at least once in a given year, although it was hard to determine exactly how often and when the event occurred. Most of the parents thought it was acceptable to leave their children even for a short moment (up to 3 minutes) because they were only gone for a few minutes to quickly grab something from the store or their house. They mentioned that it would be too much of a hassle getting their children in and out of their car seats or disturbing their children from slumber just for a few minutes of errands. One parent mentioned that depending on the age of their child, it will determine how likely they are to leave them alone in the vehicle (the older they are, the more willing the parent would be to leave them in the vehicle alone).

When asked about any proactive measures parents take to ensure that they do not forget their children in the vehicle, some examples include:

  • Actively talking to their children
  • Keeping their children in a direct line of sight (via mirrors)
  • Checking mirrors and seats when exiting the vehicle
  • Performing a mental checklist

All parents reported that it is not at all likely that they would leave their child alone in a vehicle longer than they intended to and that it is not at all likely that the child would gain access to or enter their vehicle without their knowledge given the children’s young age.

In general (based on all 18 respondents), the top reasons why participants thought caregivers leave their children alone in the vehicles were because the caregiver was distracted / negligent or too overwhelmed that they forgot, doing some quick errands, and/or the inconvenience of taking the children in and out of the vehicle.

When participants were asked what they would do if they encountered a child alone in a vehicle during a warm and sunny day as a passerby, the majority reported that they would first try to determine the health status of the children and depending on the urgency of the situation, they would either monitor the situation and try to find the parents, break the windows immediately, and/or call the police for further assistance. All participants reported that it is a serious problem to leave a child alone in a vehicle and most were aware of the fatalities related to PVH through the media or the news. Despite their awareness of these fatalities, two-thirds (12) reported never seeing any awareness and prevention campaigns related to PVH.

Participants were asked about their opinion on technology that would be most effective at warning them if/when a child was forgotten in the vehicle. The most effective technology would have warnings outside of the vehicle (using sound and lights to alert them), warnings on the dashboard when turning off the vehicle and having alerts sent to their mobile device via an app. Most of the participants were extremely willing to adopt one or more of these technologies; however, participants were more hesitant to pay extra for them (10 yes / 5 no / 3 maybe). All except one participant currently do not use any technology or have a vehicle equipped with technology to help with potentially forgotten children (many of them were unaware such technology existed!). The one participant reported their vehicle is equipped with a rear-door logic system where a reminder to check the back seat is presented on the dashboard when it is turned off.

Lessons Learned from these Preliminary Findings

These preliminary findings provide insights on caregivers’ safety perception and opinions about PVH. However, there are a few areas of this research that can be further explored. As mentioned, there is a lack of research on PVH incidences in Canada limiting our understanding of circumstances around PVH cases, the risks associated with PVH, and the main contributing factors (4). The results from this questionnaire gave a small insight into these key research questions. However, more work is needed to gain a firm understanding of these key issues to develop effective countermeasures. It would be interesting to see if there are any differences in attitudes and perceptions of parents in Canada (e.g., cold weather, cultural attitudes) compared to data gathered from the US.

A limitation of this study’s methodology was the in-person interview for collecting data. It was noted that many of the caregivers were hesitant to admit that they left their children in vehicles and that they felt like the fatalities related to PVH would never happen to them, similarities that were also found in the US (9). A self-reported questionnaire administered online may yield more candid results and a larger sample size. Although participants were aware of the fatalities related to PVH, many did not know about the various awareness and prevention campaigns. The science fair was a great opportunity to educate participants about PVH but a more collaborative and interactive approach outside of social media may be beneficial in promoting the campaigns.

When it comes to countermeasures, there are promising opportunities to equip vehicles with technologies, such as occupant monitoring systems to help detect forgotten passengers. Parents are very open to the idea of using these technologies; however, there is hesitation in paying extra for the systems. Making these technologies a requirement in vehicles might encourage parents to adopt these technologies, but it may also be greatly beneficial to countering and preventing cases of PVH. This research will help determine if the available technology is up to the task of preventing cases of PVH. If so, the research will also help to inform us about potential regulatory performance test methods and pass/fail criteria. Although there is already technology in the market (either from the vehicle or after-market products), research is needed to evaluate these systems to determine which approaches are most effective at detecting and safely responding to children in vehicles.

Research on evaluating currently available PVH technological countermeasures

Since 2023, Transport Canada has been actively working with the National Research Council Canada (NRC) on identifying and assessing potential technical countermeasures for PVH. Occupant Monitoring Systems (OMS) are promising in-vehicle technology to prevent fatalities from PVH. These systems use cameras and other sensors to detect the presence and condition of occupants. Upon detecting an occupant left in a vehicle, systems notify the driver and potentially activate other countermeasures to reduce heat in the vehicle such as controlling the climate system.

There has been some activity in the US to require child safety alert systems in vehicles (e.g., Hot Cars Act of 2021 [12]) and many manufacturers have made a voluntary commitment to equip their vehicles with this technology. Canada currently does not have such policies or acts in place. While this commitment is encouraging, there is a need to assess the effectiveness of these technologies in preventing PVH injuries and deaths. The detection of children left behind is only part of the challenge. This information must then be quickly and reliably communicated to the drivers through an effective warning interface that enables them to make a fast and appropriate response.

Design guidance is needed for both the detection and warning components of occupant detection systems. Test methods and safety performance criteria are also required to evaluate their effectiveness. The primary objectives of this project are to:

  • Review current PVH technological countermeasures (aftermarket and original equipment manufacturer (OEM) systems)
  • Select candidate systems for testing and evaluation
  • Develop a standardized testing methodology for assessing countermeasures
  • Conduct tests on candidate systems and vehicles

There are two types of countermeasures: 1) aftermarket systems and 2) OEM systems. Aftermarket systems are devices that are available to purchase separately, like other consumer products, and do not come with vehicles as original equipment. TC does not regulate aftermarket products, with the exception of child restraint systems, and some other unrelated equipment. Some examples of aftermarket PVH countermeasures include:

  • Visual aids (e.g., cameras and mirrors)
  • Clip sensors that are triggered when:
    • Chest clip being unbuckled
    • Ambient temperature outside above 35°C or below 7°C
    • Child seated for an extended period of time
    • Child left unattended
  • Pressure-based sensors
  • CO2 monitoring systems​

OEM systems are included with the vehicle at purchase either as standard equipment or an upgrade. These systems include:

  • Door-logic systems (reminders to driver at the end of their trip when engine is turned off and rear-door was opened at the beginning of their trip)
  • Sensors
    • Ultrasonic (emits high-frequency sound to capture the echo of nearby objects)
    • Camera
    • mmWave radar (electromagnetic waves used to penetrate obstructions to detect both heartbeat and breathing)

Both aftermarket and OEM systems will be selected for testing. Candidate systems will be selected from each category to cover the wide range of OMS technology available. The 4activeOD-newborn dummy will be used to test the OMS ability to detect child presence in the vehicle (Figure 2). This state-of-the-art test dummy is designed to evaluate the performance of child presence detection systems and has realistic radar-, infrared- and camera- response, with human-like behaviour including breathing, limb and head movement.

Figure 2. 4activeOD-newborn dummy to be used for testing proposed OMS technologies

NRC has developed an assessment protocol to evaluate system efficacy under the three key scenarios contributing to PVH incidents: 1) when a child is forgotten in the vehicle; 2) when the child gains access to the vehicle; and 3) and when they are intentionally left in the vehicle unattended (13). The test method will accommodate the evaluation of both aftermarket and OEM systems (Figure 3). This work is currently ongoing and expected to be completed by 2025. The results of this research will help to guide best practices in PVH prevention and inform policy.

Figure 3. Test method developed by NRC to be used for testing OMS (14)

How to design an effective warning that is not ignored or disabled because it is annoying

It is also important to consider how systems alert the caregiver / driver when an unattended child is detected in the vehicle for a safe outcome. OMS should detect a child in the vehicle accurately and effectively. Limiting false alarms and preventing drivers from becoming annoyed with, or ignoring, the signals can be done through a well-designed Human Machine Interface (HMI). Using different modalities for messages, depending on the context of the situation can achieve different goals. For example, auditory warnings should be used for short simple messages that require quick immediate action while visual warnings are best for presenting complex information. Multimodal messages (e.g., the combination of audio and visual or vibration) are generally more effective during time sensitive situations (15). There are also different factors mediating warning effectiveness such as driver state (impaired, distracted, annoyed, etc.), vehicle and road environment, and design of the warning (size, location, colour), that should be taken into consideration (16-17).

Conclusion

Transport Canada is actively making efforts in addressing PVH and evaluating potential countermeasures through awareness campaigns, engaging key stakeholders, and collaborative research. The efforts have resulted in ongoing collaborative research with other Canadian groups (e.g., NRC), ongoing presence on social media about PVH, and active participation in key stakeholder groups nationally and internationally such as the U.S. National Safety Council PVH Stakeholder Workgroup and the UNECE World Forum for Harmonization of Vehicle Regulations (WP.29) to addressing and supporting potential mitigation strategies to preventing PVH via technology. We are progressively gaining insights on the subject with Canadian researchers and collaborations. However, there is still a gap in PVH incidences, scenarios, and knowledge specific to Canadian datasets and incidents. Insights from this research can help to guide best practices in PVH prevention and inform policy development specific to Canada.

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Author Biographies:

Caroll Lau – Human Factors Specialist at Transport Canada

Caroll Lau has been with Transport Canada (TC) since 2016 where she is involved in research projects that focus on human factors related topics, such as distraction, human machine interfaces in SAE L2 automated vehicles, and safety perceptions and opinions interacting with a variety of advanced technologies (vulnerable road user detection systems in heavy duty vehicles, low speed automated shuttles, pediatric vehicular heatstroke, driver monitoring systems, etc.) The research conducted supports the development of standards, guidelines, and regulations on a national and international basis. Caroll has a M.Sc. degree in Neuroscience and Applied Cognitive Sciences from the University of Guelph and a B.Sc. (specializing in Research) in Psychology from Wilfrid Laurier University.

Patrick Kehoe – Senior Researcher at the National Research Council Canada

Patrick Kehoe joined the National Research Council Canada in 2012 where he has been involved in the mechanical design and integration of equipment on ground vehicles, structural analysis, and vibration testing. Patrick’s current role involves research in vehicle structural durability, ride quality, and improving safety of vehicles through the integration of safety systems to reduce the risk to drivers, passengers, and vulnerable road users. Patrick has a M.A.Sc. in Mechanical Engineering and B.Eng. in Mechanical engineering from Carleton University.

Zuzanna Strom – Manager, Consumer Awareness and Road Users at Transport Canada

Zuzanna Strom has been working at Transport Canada since 2018. Her current role includes advancing consumer awareness efforts on road safety and the protection of road users. This includes enhancing public awareness of key road safety risks including impaired driving, distracted driving, and pediatric vehicular heatstroke, and advancing Transport Canada’s road safety mandate at domestic and international forums. Zuzanna Strom has an M.A. in International Affairs from the Norman Paterson School of International Affairs, Carleton University, and a B.A. in Political Science and Criminal Justice from the University of Guelph.