Memo to men… if you’re in South America beware of the wandering spider. You do not – repeat, do not – want to get bitten by this bad boy.

If you do happen to get on the wrong side of the world’s most venomous arachnoid, the long-lasting consequences don’t bear thinking about.

News of this eight legged monster emerged on BBC2’s awesome Steve Backshall’s Extreme Mountain Challenge when the star of the show found one in the jungle and revealed: “It causes an endless erection and after three days you’ll probably have total loss of sexual function for the rest of your life.” Hard to take.

Intrepid Steve is one of those people who don’t have the slightest fear of creepy crawlies. Even the massive mega-bugs that make the rain forest a no-go zone for chronic entomophobes like me.

“Oh wow!” gasped TV’s top insect-lover as he stumbled upon a horrifyingly huge tarantula hawk wasp, a giant jet black beast as big as a fist. Christ.

But what a terrific mini-series this is. Backshall and a team of top rock climbers attempting to ascend one of Venezuela’s towering tepuis. Imposing sheer-sided islands in the sky that, shrouded in cloud, look like a sinister scene from your worst nightmare.

Authentic drama as the palpably daunted mountaineers lost their grip on crumbling rocks as slippery as oil, braved a fierce electric storm and tried to sleep on a precarious ledge infested with scorpions.

“I’ve been climbing for 20 years and I’ve never seen anyone try to climb something like this,” said Steve. “It may be simply impossible. I am genuinely nervous, bordering on scared.” You could tell he meant it.

They estimated it would take them five days to make it to the top. But after the tense first episode the question is: will they make it all? Watch this space.