Liz - No-one has advocated boiling the Toddy! The instruction is to make it as hot as you possibly can. Consequently, I recommend flashing it, as necessary, to bring it up to heat once it's mixed. As to "lemon wedge", a waste. Juice of a lemon, boyzngurls, a whole lemon! Or lime. A wedge is merely cosmetic & will do you very little good. This is medicine we're talking about, not a damn cocktail!

Poppa - Single malt is drinking whisky. It's made to be drunk & enjoyed for itself & its own flavour. Add water, if desired (hot or cold), but nothing else. It also, as a rule, costs 2-3 times as much as blended whisky. Blended whisky is made from those malts that aren't good enough to be drunk as singles. Because they are blended to even out irregularities in flavour, it happens that they also blend well with other drinks.

If you want to drink a Whisky Mac (whisky & ginger wine), you don't Mac a single. Whisky & coke/lemonade/any other mixer, you use a blend. The point of singles is that they are to be appreciated for their own sake. So, since a Toddy is not only a mix, but a mix for medicinal purposes, why the hell would waste a single on it?

I can't stop you using a single malt for a Toddy, but you're wasting money & good whisky. You're not drinking the Toddy for flavour, remember. You're sipping it as hot as possible for medicinal effect! As long as your whisky isn't equivalent to meths or paint-stripper, it doesn't matter whether it's cheap or expensive...

And, if doesn't matter, why waste the more expensive whisky? Bells, for the Yookers, makes a very good Toddy, but I wouldn't drink it straight (& I'm on Claret-aged Speyside single just now...)!