I'm sure this has been covered, but a search of "heat" didn't really come up with what I was looking for.

The weather report here predicts 105 degrees plus the next few days and the health department has issued warnings stay in doors.
I have thrown up from heat just waiting for a bus. But, I've found I can ride in the head with less of an issue
I usually ride to work a few days a week, and really want to ride in tomorrow. It'll be 70-ish on the way in and over 100 on the way home. It's usually upper 80s to lower 90s for the commute home.
Is there a health issue, am I being foolhardy trying to ride in that heat?