The latest research says that a cooling vest can improve a 5km run time by on average 13 seconds.
S.A. Arngrimsson et al. Cooling vest worn during active warm-up improves
5-km run performance in the heat. Journal of Applied Physiology
Skin temperature decreases rapidly once the Arctic Heat
Cooling Vest is applied - even when used over the
clothing the skin temperature reduction can be as much
as 54 ° F.
Less total cardiac output is directed
towards the skin, allowing more blood to be directed
towards active muscles.
Arctic Heat Cooling Vests serve to
conserve fluids which would normally have been lost in
the form of sweat.
Arctic Heat Cooling vests delay the
onset of dehydration and performance decrement.