Doubtful or there would be many dead. CamelBak reps made a big deal about drinking cold water while engaged in activity in hot climes. Their caution was cold water 'doesn't quench your thirst' as well as tepid. But they had no answer for why they had expanded their fill spouts to enable the use of ice.....just like all the boys fighting in Iraq did when they could get it.
Thanks! I’ll go with no and use ice whenever I want. (Which is not often.)
Water uptake in the stomach is more efficient when the water is cold.