I have seen several bee hives this week with white boards still in. When it's summer and the temps are in the 60's or higher (92 today), there is no need to leave the white boards in. They should only be needed after a mite treatment for a day or two at this time of year.
Additionally, vent boxes should be used on the top of the hives to allow air flow.
Lastly, there is no need to have entrance reducers on your hives at this time of year.
The bees need all the air flow they can get. This weekend, they are working overtime to cool their hives, give them a helping hand.