Hello,
I'm 4 weeks myself, and asked my GP this very question yesterday!
He said that I'm fine to continue as before, but to avoid any contact sports.
I specifically asked about the raising of temperature too, as I had also heard that it was dangerous to overheat.
I have been advised that whilst the increase in core temperature from a virus could be an issue, getting hot/sweaty through exercise is never going to be a problem.
He said that as long as you are sweating, then this will cool your body down so that your core temperature will not get anywhere near the 'danger zone'.
Unfortunately, this diversion of blood flow to the skin (along with the diversion to your uterus) can make you feel a bit faint and dizzy, so definitely listen to your body and stop if you feel you need to.
His advice was that the very significant benefits to me and the baby from a good cardio workout far outweighed any risk from overheating.
That said, I am just back from the gym (in an attempt to shift this horrible headache I seem to have) and I managed about 1/10 of my usual intensity of workout. Perhaps nature has a way of self-regulating these things?