How cold is the water you are entering? As with alcohol, the cold can seriously affect your ability to think rationally, it can sap your strength extremely quickly and you lose your fine and gross motor skills. A recent study has suggested that with the water temperature at 32.5 F/0.3C, an average person will only remain conscious for 15 minutes. The water may not be too cold initially; however the duration that you are in that water for can still sap body heat over a period of time. Think about how long you will be in the water for.