i tend to prune whenever i want ..

i dont know what heat or drought would have to do with taking off limbs

ken

The degree of pruning can elevate heat stress which can the further weaken a tree making it more suseptiable to insect invasion. Aren't dogwood borers on the hunt?

Pictures will save alot of Q&A to help determine if you can prune now or later.

If we're talking a few dead limbs, prune now.
If we're talking pruning a limb that is hitting you in the head, prune now.
If we're talking thinning of the canopy, prune later.