Helps some. Putting Water on roof with drip hose works better but water can get high, leave off a run or two helps also.
I had never heard of cooling vests until now. Here is a comparison of some. http://www.activemsers.org/tipstricks/choosingacoolingvest.html
I have used the Texas Cool Vests which uses phase change materials to keep the trunk of the body cool. It's good that it's not cold which would be uncomfortable. But it does extend the amount of time I can spend in a hot attic. But you have to realize that it is not going to make you feel chilly! Just a bit more comfortable for a longer time.
Paul I appreciate your reply. That is the kind of info I'm looking for. If I can just make it more tolerable (survivable) come this summer.
Thanks Mike Hartnett
Fortunately I no longer have to deal with those extreme temps, hiding in Maine, but I do remember some of that heat from when I worked in NJ and I bet you are dealing with higher temps than we saw. What I have always wondered is, would it be practical to park a large commercial size air conditioner in the driveway and run a 16" flex duct somehow into those super hot attics? I haven't played with the cooling numbers, but when it is that hot, anything would help.
I realize this wouldn't be a low cost solution, but sending employees into an oven creates all kinds of safety risks. Not sure where OSHA stands on the temps people are allowed to work in.
On a related note, OSHA has this Phone App to help crews anticipate and deal with heat illness:
I have not tried the cooling vest. I can extend the working time in an attic by pressurizing the house with the blower door and leaving the attic hatch open. It can still get hot but what a relief when you get next to the hatch and have a nice cooling wind blowing.
These type vests have been used by motorcycle riders for many years. Consensus is that they work well in low humidity conditions; less so in high humidity conditions, but always need airflow to create the evaporative cooling. Not sure how this would be accomplished in an attic unless you had a fan (which would kick up a lot of dust). There is a lot of information available from cycle riders as to what clothing works well to provide comfort in many extremes (with cotton being the worst) so maybe the best attic attire is the extreme heat high-performance gear by Under Armor and others (covered by some version of high-performance/high-wear outerwear like 5.11 pants - not cotton jeans) combined with frequent hydration.
Phase changing cooling vest work great, my weatherization crews wears them all the time. They work like ice packs but at 60degrees. Cool to the body but not ice cold. We keep a cooler of ice water and a 2nd cooling packs in the trucks. They last about 3 to 8 hours between recharging packs in ice water. Recharge time 45 minutes. There’s little to no condensation on the vest and a lot less sweat on the body. We us the RPCM cool vest, here’s a link http://www.coolvest.com