The U.S. officials took the step Thursday of warning people on or boarding airplanes to not turn on or charge the new Samsung 7’s during flights. Their have been incidents of them catching on fire.

The U.S. officials also warned passengers not to put their Galaxy Note 7 phones in their checked bags.

It is extremely unusual for the FAA to warn passengers about a specific product.

Samsung had launched the latest version of the Note series in August. The Notes are one of the most expensive series released by Samsung.

Before the issue of battery explosions emerged, supplies were not being kept up with such a high demand for the smartphone.

On the bright but still dark side the Note 7 is not the only electronic to catch fire thanks to lithium-battery problems. Other electronics that have caught fire are laptops, and Telsa cars.

Rechargeable lithium batteries are more likely to overheat rather than other types of batteries. If these batteries are exposed to high temperatures, are damaged or have manufacturing flaws they are more than likely to catch on fire. Once the overheating starts, it can lead to “thermal runaway” which means temperatures continue to rise to very high levels. Water can put out the flames, but doesn’t always stop the thermal runaway. They say flames will often reappear after initially being drowned in water.

Lithium batteries have become popular in consumer electronic devices. Manufacturers like them because they weigh less and pack alot more energy into the same space than other types of batteries.