Exercising when ill?

I always say that you should exercise while you can because you never know when you will get ill.
I´m not sure about you but when I get ill I get really ill. So for me to even think about exercising is far away. I also think that it´s better to stay in bed one day instead of tiring yourself and then have to stay in bed for a week.
When you get ill your Body is telling you that it needs more attention. So why would you not listen to your body but instead go for a work out and make it even more tired?
But how do you know if it is safe for you to work out?
If you have a fever it is not advised to exercise, same thing goes for coughs and if you are feeling sick. If you have a runny nose for example you should be OK. If your body tells you that it is in pain then do yourself a favor and stay in bed.
If you decide to exercise still then you might put yourself in a greater risk to cause serious damage to your body and heart.
But don´t let your illness stop you from getting back into your training routine. Even more reasons to continue, to build up a strong resistance for future illnesses.
I´m ill at the moment so the only exercise I will do is watching The PAN Games on TV.
Take it easy if you are ill. You can always work out another day.
I work out if I have a head cold, but if my body aches I stay in bed.