possibly a stupid question!

I haven't taped many outdoor festivals and the ones I have done are mostly in tents.
This summer I plan on doing a few long festivals out in the (hopefully) sunny weather for hours and hours. I am running two rigs - Busman bsc1 and also Church Audio CA14 omnis.
Should I be concerned about the mics being out in the hot sun for 6+ hours for multiple days? I have seen others use umbrellas on hot days, but I wasn't sure if this was only for certain mics or some other reason.
Will the mics get "too hot", or doe sit not matter?