Visor or Cap - Hot Race

I always wear a hat for the exact reason you state.

This strategy was reinforced by my fried, a 7 time kona qualifier Ben Widoff (yes, Cam Widoff's brother)...he told me that ice in a hat on a hot day is cooler than no ice and no hat on a hot day.

If you can, experiment with both.

I tend to wear a vision in training and shorter races because i just dump water on my head.  I did wear a hat during Ironman for the reasons you stated.  I tried putting a sponge in the hat but that didn't seem to work. 

I like to wear a visor because I feel like it lets a lot more heat out and keeps my body cooler.

When I run with a hat in the winter I can tell my body is warmer. So to me letting more heat out keeps your body core lower.

I think it is all a personal preference.....

Ice in ones cap during a hot HIM run can be a glorious, magical thing...
 
I've done 3 HIMs and temps were in the 90's for all of them by the time I hit the run course (the winners had eaten, showered and their flights home were landing by this point).  

At the last race, I forgot my hat.  I so missed being able to put ice in it.

And just in case anyone's wondering, my next HIM will probably be the Tupper Lake Tinman. So if you want to avoid the heat, consider yourself warned.

I wear a hat when its going to be hot just for holding ice.  I did MM last year and yes it was a hot one during the run with no clouds and ton of open space.  I have two hats that I'll wear, one is a Desoto brim hat that has a mesh opening at the top of the hat to draw out heat and the other is a Nike dri-fit hat.   I prefer the Desoto hat for long events and when it sunny, it'll also hold more ice!  Sadly it's not available anymore.

A hat because:

• I don't need the top of my head burned
• It helps keep the sweat from running in my face
• A good place for ice. At my IM in August, I kept a baggie full of ice in it that I refilled at every aid station.

I have found that the UA running hat does a better job than the Nike dri-fit at keeping the sweat from running down my face.

I run with a visor for HAIR reasons

As a guy it's probably no hassle to you.  So go with a cap. 

But with a longer mane...  there's the pony tail to consider.  It's most probably been warped due to the swim and "helmet hair" ... so a Visor is much easier to get on your head in transition without either retying a pony tail or pushing it up or down. 

I'm only using it to protect my face and eyes from the sun.  (I burn very easily and where I live has the highest rate of skin cancer per person than anywhere else in the world) 

The visor provides no cooling benefit.   

Thanks for all your replies, it all make sense.  I always use a Visor (I have 3 of them) and I also have a HeadSweat Cap from St Croix, I think I'm going to use that.

Thanks!