Forget crocodiles, sharks, or insects that make you bleed through your arse, Bear Grylls is the scariest thing on TV.

In truth, at first glance ex-Etonian Bear, or 'Edward Michael', as his mother likes to call him, hardly looks like the stuff of nightmares. He has an accent that would shatter glass and looks more like a well-intentioned Geography teacher than an action hero.

But anybody who has tuned into his Bear Grylls: Born Survivor series on the Discovery Channel knows exactly what we're talking about.

The premise for the programme is quite ridiculous. Basically, every week Grylls is dumped in an extreme location somewhere around the world and armed with only his wits and whatever food he can lay his hands on has to make it back to civilisation.

What we have never been sure about is whether this is intended to educate or just titillate. Indeed, the chances of you somehow ending up in the stranded middle of a tropical jungle or the Sahara desert are somewhat slim. Thinner still is the possibility of you replicating the former SAS hero, who lists climbing Everest among his many impressive achievements.

Got to climb a 50ft waterfall? No problem. Apparently, it's all about picking the correct starting point. Got to abseil down a 20ft ravine? It's easy. Just make sure you get your legs in the right position. Got to make a raft from only four twigs and well-positioned flask? It's simple. Simple? Oh fuck off Grylls, you posh cunt.

Actually, thinking about it, in terms of survival, shouting abuse at Bear is the last thing you should do. Obviously, years of abuse at school for being the son of a Tory politician – the late Sir Michael Grylls – has left its toll on the action man, who has learned to cope in extreme conditions by turning himself from the shy, mild-mannered 'Edward Michael' into the ferocious 'Bear'.

This is why he is the scariest thing on TV. Placed in any extreme situation and everything becomes food, shelter or firewood – the Bear necessities (see what we did there).

He has drunk water from elephant dung, sunk his teeth into rotting zebra carcasses and even licked the tears of vanquished ants. Abuse him and you could be next. But at least you would die in the knowledge that none of your body parts would go to waste. He would turn your eyes and teeth into a handy bivouac, harvest your hair for firewood and then make his escape by turning your rib cage into a trusty canoe.

It's pretty addictive viewing, however, and Grylls makes fellow survivalist Ray Mears seem like a kindly, eccentric uncle. Indeed, Mears would need a strobe light to move that fast.