If you feel like it would get to hot for them you can watch for any signs of hotness which would be staying on the sides (walls) of wherever you putting them (unless your just put them on your yard) and they could also start panting (breathing with mouth open)
They need access to deep shade to help them cool off. The electrolytes should help a bit too. Yes high temperatures can be problematic for chickens in general, regardless of age. Chicks can't regulate their body temperature as well as adults.
Thank you! The coop is located right under a tree so it gets dappled shade for basically the whole day. We tried to limit our time near the coop so they wouldn't hear us and get worked up (they know I'm the treat lady). We placed some ice cubes in their waterer, gave them a second cold waterer and right before they started settling down for sleep, we gave them watermelon to ensure they got extra water today. Also placed a fan outside the coop ventilation area to also make sure the air was moving in that area. It was a busy and stressful day but I appreciate all your responses!!