Before you hit the sack tonight with your cell phone right next to your bed, check this out from Health.com.

A recent study says 44% of us sometimes or always sleep with our cell phone within reach.  Because we like to watch stuff before bed, play games and use it as an alarm clock.  But here are three reasons NOT to.

1.  We still don't know the health risks.  The general consensus is they're safe, because they only give off a very small amount of radiation.

But in 2011, the World Health Organization listed smartphones as a possible carcinogen.  Meaning we're still not sure if they cause cancer.  Especially in kids, because their skulls are thinner, and let more radiation through.

2.  It messed with your sleep.  The screens on cell phones and tablets give off something called "blue light", which has a wavelength similar to sunlight.  And studies have found that it tricks your body into thinking it's daytime.

So you shouldn't stare at your phone right before bed, because it makes your body create less melatonin, which is a hormone that makes you sleepy.

3.  You could set your bed on fire.  A girl in Texas recently woke up to a burning smell, because she'd slid her Samsung Galaxy phone under her pillow.  It ended up melting part of the pillow, burning her sheets, and scorching her mattress.  It was probably because she was using a generic replacement battery.  But there's also a 24-year-old woman in England who says she recently fell asleep on her iPhone while it was charging, and it severely burned her chest.