I'm with
Fugro airborne and dehydration is a safety issue for us, especially in hot weather environment or, during our long low level survey flights.
I was given this "memo" on my last medical :
WATER REQUIREMENT FOR HUMANS
8 glasses of water is the normal daily requirement for an average sedentary person. However, if you get involved in various activities, your requirement goes up. How much it goes up depends upon your weight, your gender, the surronding temperature and humidity, how fit you are and how intensely you're working.
Based on a 135 pound active person, the following will give an estimate of how much extra fluid is lost in some examples of other activities.
ACTIVITY---------------------------------------------EXTRA 8 OZ GLASSES
--------------------------------------------------------OF WATER NEEDED
5 hrs airline flight (only as a pax)------------------------------4 - 5
Sitting at an afternoon balgame, 3 hrs, 32C-----------------2½ - 5
Watching the ballgame at home on TV, 3 hrs----------------1 - 2
Swimming 1 hr, pool temperature, 20C-----------------------½ - 2
Walking 1 hr, indoor treadmill, 21C----------------------------1½ - 2½
Walking 1 hr, outdoors, 30C------------------------------------2 - 3½
Hiking 4 hrs, rolling hills, 20C-----------------------------------10 - 14
Hiking 4 hrs, rolling hills, 30C-----------------------------------13 - 16
Running 1 hr, 6 mph, 30C---------------------------------------5
Tennis 1 hr---------------------------------------------------------2 - 10
Sleeping 2½ extra hrs-------------------------------------------½
End of the memo.
The next safety issue related to water for us (as we are often in remote areas) is to be sure to drink "clean water" but that's another topic.