Foreman told me to stop soaking bricks on a job in Bakersfield, and he was right, so I changed how I lay in summer heat | Bricklayers - Chatter Central
A foreman in Bakersfield in July telling you to quit soaking is basically telling you to watch your mortar turn to dust before you can get a brick set. Soaking does more than just cool the brick down, it keeps the brick from sucking the water right out of your mortar so you actually get a bond instead of a dry crumbly joint. Maybe in your case the bricks were already wet from the stack or you were mixing hotter than usual, but writing off soaking as a summer rule sounds like a good way to buy back a bunch of callbacks.