Pediatric vehicular heatstroke occurs when body temperature exceeds 104°F, with children’s body temperatures rising three to five times faster than adults’. An average of 37 pediatric vehicular heatstroke fatalities occur yearly from 1998-2024, primarily from children being forgotten in vehicles. NHTSA has tested retrofit, aftermarket, and vehicle manufacturer unattended child reminder systems using direct and indirect sensing approaches. Testing revealed Bluetooth-connected devices alert at varying distances depending on signal strength, capacitive and pressure devices face false trigger risks, and direct sensing radar systems show inconsistent detection across vehicles and seating positions. NHTSA plans to publish an Advanced Notice of Proposed Rulemaking seeking comments on amending Federal Motor Vehicle Safety Standards to require rear seat occupant detection systems.