White phosphorous is nasty stuff. During WWII, my uncles regiment were equipped with No. 74 grenades. Sticky bomb - Wikipedia, the free encyclopedia
As the article says: if the user was not careful after freeing the grenade from its casing, it could easily stick to his uniform.
This happened several times during 'live ammo' training. Afterthe second time, an order was sent out to shoot anyone it happened to before the bomb ignited - there was literally nothing else they could do and anybody with a no 74 stuck to their clothes was a dead man walking. Eventually. Death from phosphorous burns can take hours.