1st cold ride of the year wasn't that cold (32 degrees F) but I still warmed my water & used an insulated water bottle. used filtered water warmed in a tea kettle. not hot enough to steam, just "warm". sorry, didn't use a thermometer. sprinkled in a little salt & lemon juice. rode for just under 2 hrs. it stayed warm for the 1st half & wasn't "cold" until 4 miles from home