I am not a doctor and maybe one of us out there is a doctor and could
add to this. I have been informed by rangers at the Grand Canyon that at
temps over 80 to 90 deg F that your body can not replace the water quick
enough that you sweat out when you are hiking. That is the reason
that so many people are resqued from the canyon during the summer months.
In fact some summer they have closed the canyon to hiking between the hours
of 7 AM to 7 PM because the rangers were endanger from heat stress injures.
Grand Canyon National Park
- Search And Rescue Statistics
I bailed at Cibbits Flat with classic heat exhaustion
symptoms even though I was guzzling water at an alarming rate.
.