Christmas warning: if you do decide to brave the sales today and have on your list a new winter coat, be afraid. They don't make winter coats like they used to. The new ones, the duck-down ones, were designed for a post-nuclear ice age. They will literally boil you alive. This year I predict the so-called 'puffa' jacket will be the number one killer amongst men of a certain age.

When did ducks get so hot? We can point to the moon landings for all the improvements in science-related things, but what was the equivalent in the duck world? The modern duck-down puffa jacket is like something Q would slip to James Bond. Ducks have made advances in heat retention that no one can either explain or understand.

I know this to my cost. I'd wanted a new coat and had been envious of one I'd seen at a football match; we'd all been freezing, but one man, in said puffa, was obviously as snug as the proverbial bug.

So I kept pressing the sales assistant: "Anything just a little bit warmer? You know, just a few more tog to it than the others? I can handle it."

"Step this way," he said, opening a door to a place where they kept the real stuff.

There was even a menu of sorts with photographs of three ducks. One looked pleasantly warm, one was sweating a little, and the third was actually a roast duck complete with spuds and an orange sauce. It was steaming. "I'll have the one he was wearing," I said. "That's the coat for me!"

The sales assistant was nervous: "A level three?" he said. "Tog rating: 16 million to the power of nine?"

"Good," I said. "You can't be too toasty."

I was wrong. Putting it on was like stepping into the pages of a JWT summer holiday brochure with the girl in the yellow bikini that brought this country to a halt in the mid-'80s. It was like she was in the coat with you. The puffa design did make me look a little like the Michelin man, but what of it? I was the warmest Michelin man in the world and that was all that mattered.

"I'll wear it out," I told the assistant.

This was my second – and indeed fatal – error. I'd reached 104 degrees by the time I reached the exit. Rivers of sweat were cascading down my back.

I whipped the coat off but immediately felt the chill wind freezing the pools of perspiration. So I decided to zip it back up, run back to the assistant and claim a level two instead.

The last thing I remembered was steam escaping through the sleeves.

As I lay on the floor of the shop, a gentle voice was heard to offer me water. I was just returning to consciousness and trying to sit up to hold the glass when another more dominant voice boomed, "Keep him warm at all costs. Keep his jacket zipped up – and here, put this duvet over him as well."

The last thing I saw before I closed my eyes for good was the sweating duck logo on the duvet. "Ah shite," I whispered, and expired, or melted, hard to say which.