Bad Hot Day

Well, today was supposedly 3 degrees F cooler than  yesterday but I lost 5 rabbits from the heat.  This upsets me greatly because last summer was hotter with much higher humidity and I didn't lose any rabbits.  3 of my good breeding does, a 7 month old buck and a 2 month old doe.  Her 3 siblings are fine, they were all in the same hutch.  I hate losing critters.