It's unlikely you will ever have to worry about a grenade going off near you, but who knows — that post-apocalyptic scenario we all keep joking about could be right around the corner. This video explains how a grenade works and how you can lower your chances of being injured if one explodes nearby.
In this video, youtubers Mark Rober and TheBackyardScientist offer some potentially life-saving advice when it comes to the typical frag grenade. As they explain above, the shrapnel (or fragments) from the grenade is the most dangerous part, not the blast itself.
So, if you see one fall to the ground near you, it's time to hit the deck. Turn and face away from the grenade, get at least 5m away, then lay on your stomach with the flat parts of your feet pointing toward the grenade.
That will significantly reduce the chance of shrapnel hitting you and if it does, there's a chance it will hit the soles of your shoes, not your flesh. Also, if you see one fall into the water you're swimming in, get out — don't dive deeper. In that case, the shrapnel won't get you, but the pressure created by the blast will compress your lungs and do some serious damage.
How to Survive a Grenade Blast [YouTube]