How to cope if you've got a sore throat or a cold and you have a gig coming up

An old singing teacher once told me that you can sing with a cold, it just gives your voice a different tone and texture. I have therefore always, stuck by that rule for the last 12 years or so. Sure it's not pleasant, and certainly not as enjoyable as singing with a healthy nose, but it won't do you any permanent damage. The golden rule is, (and I’m by no means a doctor nor do I have have medical training) if you have a ‘sore throat’ i.e. it hurts to talk, cough, or sing, or make any noise whatsoever, then you really should be resting your voice, and definitely not singing. As I will go on to elaborate, it really really is not worth it in the long wrong.
I always ask my students, if they do feel a little under the weather, to please let me know, particularly if their throat itself hurts. If you have a sore throat, this is where you need to be very careful. I have been stupid in the past and given myself phrangitis and laryngitis for over doing it and burning the candle at both ends. I have also tried to sing while coming out of the end of a horrible dose of tonsillitis, only to make myself worse and even more ill, all for the sake of ‘one more little gig.’ Go and see a doctor, and seriously take their advice. Don't think to yourself, 'oh just one more little gig,' because you will only make yourself worse. It really isn't worth it at all in the long run. That ‘one more little gig’ could cost you another five until you put yourself right. Last year, I worked out I lost a weeks wages from being ill, therefore cancelling gigs and lessons, not to mention prescriptions and tablets just to get me back on my feet.
My advice is: a slice of lemon and a tablespoon of mild honey with boiling water, let it steep as much as you would your teabag, remove, then a little bit of cold water to even the temperature. Sanderson's mixture tastes like pure hell, but its the best thing in the world. Strepsils, soothers etc are a waste of money in my opinion. They taste nice, but because they are full of sugar. Sweets like these often contain a little bit of menthol, and so give you a bit of instant relief, but aren’t effective in the long run. I’ve found that Ricola sweets taste lovely, and are also pretty good, as well as Jameson’s cough sweets (honey and lemon and blackcurrent are my favourite, I hate the original and cherry!) The best thing though is gargling Sanderson’s solution with water. It tastes absolutely horrendous, but it is magic. At the end of the day, though, lots and lots of water, and plenty of rest are the best medicine, as well as fresh fruit juice.
Ways to prevent throat problems is a hard question, because we are all only human, and there are always nasty bugs going around in the air. Obviously advice is, and especially during the colder months is to keep clean. Wash your hands plenty and thoroughly, which will help you avoid picking up anything. If, like most of us, you lead a busy active life style, invest in a couple of small bottles of liquid hand santiser, as they are the best way to keep your hands clean while out and about. I swear by taking vitamin C and cod liver oil tablets every morning, and have done for the last year. There is extensive research suggesting that cod liver oil makes you brain functions work more effectively, but also they are great for your immune system, and thats particularly why I take them. (Nothing in the world is going to help me get better at algebra!). My mother keeps boasting that shes taken cod liver oil every day for twenty years, and shes never once had a cold...and I honestly can vouch that that is very much true!