A device made from parts of a toy and a cell phone could save the lives of firefighters, reports the Wall Street Journal.

Temperature surges are a serious cause of firefighter deaths, two were killed in a fire in south England in 2010. Temperatures can rise hundreds of degrees in seconds if a fire is hit with a blast of air, for example when a window bursts. The risk has become worse as protection has become more effective leaving firefighters less able to sense sudden changes in temperature.

A team of six people at the recent hackathon at Imperial College, London created their winning solution. It had to warn firefighters when external temperatures reached 350° Celsius, had to be affordable, and had to fit within the firefighter’s existing kit.

Their answer: a cell phone vibrator, a heat sensor and an Arduino — a cheap computer often used in toys — built into a helmet that alerts the firefighter through vibrating the back of the neck.

This solution could come in at as little as £5 ($7) if manufactured at scale, the team calculated.

Read more of the story here http://on.wsj.com/XUQQEP