Now that the weather is hotting up a bit, what does everybody do with regards taking on fluid during races? What distance is ok without? I can normally run 6 mile/10k without carrying water, but this weekend found I really needed water during a 4 mile race because of the heat. Being a new runner who only started during the winter I've never run in the heat so I've got no idea, and the few fell/road races I've done hardly anybody carried water on less than 10 milers.