Of warm mice and screwdrivers

In winter my extremities (fingers and toes) swell up, itch and ache like hell due to poor circulation. The condition is known as Raynaud's and it's a pain in the posterior. To combat the vasospasms which cause your blood vessels to contract (vasocontriction) and reduce the blood flow, you have to induce the opposite phenomena (vasodilation) by keeping warm. I tend to blast my wrists with the hand dryer in the toilets, or run hot water over them.

You can't spend the whole of winter in the toilets so another solution is needed. That's why I bought the *commence breath-holding, drum roll* Thanko USB Warmer Mouse II. It may seem like an odd strategy considering it will only defrost one hand at a time, but it actually makes sense because the wrist you're putting pressure on by using a mouse all day long is going to be the point at which blood flow constriction is at its most severe.

So, the mouse arrived from Hong Kong, worked pretty well-ish for a few hours and then all of a sudden the cursor movement became highly erratic. The very nice, helpful Brando people promised to send me a replacement, and in the meantime I decided I'd dissect the ebbing rodent to see what makes it tick. Despite me using a screwdriver to open it up, I didn't unscrew any screws with it. There aren't any on the external housing so the mouse has to be broken open by force to see what's inside.

With the top part of the shell removed you can see that the heating element consists of a thin fibrous mat with a copper strip attached at either side. This is segregated to prevent damage to the circuitry under the second layer of the shell.

Each strip is connected to the innards of the mouse by a single red wire. I'm probably asking too much for such a cheap device, but I expected to find some sort of oil-filled miniature radiator under the hood so was underwhelmed by this scrap of material which will only radiate heat into the centre of your palm.

The only other aspect of the design worthy of note is perhaps the switch built into the USB cable. This is used to enable or disable the heat function so the mouse can also be comfortably used in summer. It does its job, but I think it was silly to place it so close to the mouse itself because it gets dragged around like a dead weight as you navigate. I might end up Blu-Tacking it to my desk when the replacement arrives.

Maybe I'd be better off buying the Finger Mouse. No awkward wrist positions or pressure should equal no constriction, though I wonder how you stop the cursor flitting back and forth across your screen like a ping-pong ball while you type. None of the reviews I've read mention this.