First ideas:
- A device that informs an oblivious runner that there is someone behind them and to GIVE WAY! (worn by runner/someone).
- A hat that gets tighter as the UV index goes up to protect you from the sun.
Expanding on the UV index hat:
- Expanding/flaring as the sun gets brighter
- The hat headband gets tighter per every level of UV (0-11+)
Weather API returning UV index: https://openweathermap.org/api/uvi
Tightening mechanism: Servo on a belt