A Facebook post (and other social media) claims that giving your dog ice or ice water on a hot day will likely cause it to die from bloating and spasms.
Officials with the Humane Society it's not true. "Reports from veterinarians and our own vet indicate that drinking ice or cold water is not inherently dangerous for dogs and does not cause bloat as claimed in the warning message. While the dog discussed in the message may have indeed suffered bloat, there is no evidence to support the claim that the condition was caused by ice. We suggest you always double check with your vet on things you're really unsure of but ice is safe."
It's also been debunked on Snopes.com: http://www.snopes.com/critters/crusader/icewater.asp#sR5ddLYT0Cs8bfBt.99http://www.snopes.com/critters/crusader/icewater.asp