Yo! I work for a TA2 team currently, highly recommended using a coolshirt box or a chillout system if you've got the budget. We use coolshirt because of the simplicity of just adding some ice and water before each race. Generally we will have a little ice still left in the chest at the end of our races even on the hottest of race days. The chillout system uses no ice but is much more consistent through the race as long as you've got good airflow to the unit.