Why are we cold after multiple days of diving?

[rmssetc]

You've probably heard the account or experienced it yourself...after several successive days of diving, you seem to get colder more easily, even if the setting is recreational diving in 80-degree water, with 80+ degree weather, thermal protection that's adequate on the first day, 2-morning dives daily with a dry wetsuit to start each day, adequate hydration, food, clothing post-diving, etc....

So, why do we feel colder on day 5 than day 1? Is it really physiological (core body temperature remains depressed 20+ hours after each day's last dive, leading to a cumulative drop--doesn't sound likely to me), psychological ('knowing' that you were chilly immediately after yesterday's dive makes you feell colder today) or something else?

 

[1000RR]

I've heard the same and will be testing the waters (literally) this March with my daughter on a livaboard. We had a dive last weekend where each 60' dive was about an hour. After the first dive we were both cold by the end... expecting the second dive to be even colder we were not 100% looking forward to it. We jumped in, descended and that 2nd dive actually seemed warmer than the first. We weren't as cold by the end and were pleasantly surprised. Water temps on the computer read about the same to maybe a degree colder.

 

[Jack Hammer]

Short version is your body needs to recover.

Even in 80+F water temps it is colder than your body temp. Water transfers heat much more efficiently than air does. People lose more heat than they would imagine in water.

 

[Stoo]

I think there are several reasons... Probably most importantly, neoprene that is repeatedly compressed takes longer to recover. This simply means that there is less insulation provided by the suit, so the diver feels the cold more.

The other factors that may come into it, especially on vacations.... inadequete sleep, perhaps a few too many drinks and the ensuing dehydration, bad diet etc...

And as someone pointed out above, liveaboards are notorious/awesome for this... just a ton of diving in a short period of time... Some people just don't get warmed up adequately and after a few days, it becomes noticeable...

I know from my own experience, (T&C EXPLORER, summer time) that I began the week diving in board shorts and a 3/5mm vest. Then I moved to a full suit. Then I added a 1/3mm hooded vest, and finally the 3/5 mm hooded vest under the 3mm suit. The water was still like soup, the air was still hot and humid, and I couldn't get warm!

 

[lowviz]

When I used to run regularly, I always had glucose tablets with me. Fast fix. Your brain steals glucose first, easy google search...

Eat well and balanced, keep supplementary glucose in reserve.