I'm not sure how a cooling vest would work for a runner. You can't really warm up on a stationary bike. Maybe doing 20 minutes of running to warm up, then wearing a cooling vest for the last 5-10 minutes before the start, jogging in place a bit, would work.
I wonder if it's possible to run with the vest, I heard some rumours about the Swedes using such a vests in WOC ... at ArcticHeat they have cooling caps also (!?)
In the World Cup in Oslo Swiss runners were wearing cooling vests just before the start. I guess for the first couple kilometres in the race you should feel better in the +30 after wearing such vest.