Bdtyktl

I surround men on all sides, I make them deaf, and I escort them to oblivion—and yet they love me. They have shed the blood of others to obtain me. I appear harmless and yet pierce those who approach me. Only come for me when all is hot and dry, or all will be lost.

What am I?

You are

space

I surround men on all sides

Space is all around us.

I make them deaf

In space, no one can hear you scream.

and I escort them to oblivion

Space kills you, unless you're wearing some kind of a suit.

and yet they love me.

Who doesn't love space?

They have shed the blood of others to obtain me

Wars have been fought for living space.

I appear harmless

Invisible, in fact.

and yet pierce those who approach me

Even atoms are mostly empty space.

Only come for me when all is hot and dry, or all will be lost.

Once the Sun expands and swallows the Earth, humans face extinction unless we've managed to escape to space before that.

I think you are:

Water

I surround men on all sides,

A reference to both water in the body and humidity in the air

I make them deaf,

Being underwater makes your hearing muffled

and I escort them to oblivion—and yet they love me.

A reference to drowning yet all of us need water to live

They have shed the blood of others to obtain me.

A reference to water wars and violence when drinking water is in short supply

I appear harmless and yet pierce those who approach me.

Piercing the lungs

Only come for me when all is hot and dry, or all will be lost.

I.e. drink water when it's hot and dry

This may fit:

Cotton

I surround men on all sides, I make them deaf, and I escort them to oblivion—and yet they love me.

Cotton is a common clothing material, cotton is used in ear plugs to reduce noise, and ear buds to remove wax are used but these can damage ears. Bed sheets are popularly cotton and escorts people to sleep.

Shed the blood of others to obtain. Appear harmless, yet pierce. Come for me when hot and dry, or lost.

Cotton was the chief plant involved in slavery and the American civil war, looks soft to pick but the dried husks cut skin. It must be harvested at the right time towards the end of summer or the crop will be lost.

A Gun

because

Men love guns.


Guns can make men deaf because of the noise they make.


Guns help men get to places through the enemies, only to find more men love guns.


Some guns look harmless but still can kill.


you only want to shoot when your gun isn't too hot, so it won't go into a melt-down.