Cold Weather Test for Water BottlesStaying hydrated in the winter is very important. It is hard to drink frozen water! Here is a simple test of waterbottle done to simulate typical conditions in Colorado.
Initial measured water temperature just before placement in the freezer was 69.8F. 850 ml of water was used for all items to prevent cracking of bottle during expansion.
The bottles were placed in the freezer at 8:07 PM October 11 2007. A digital high/low thermometer accurate to 0.1 degrees F was used to record the freezer temperature.
By morning it was found that the freezer temperature stayed between 3.5F and 7.2F throughout the night.
Average winter temperatures on Pike Peak are displayed in the following summary of the weather statistics:
Pikes Peak Weather Statistics
Of course it is often colder than average. Displayed below are some of the temperatures I have camped in the local area for each month of the year:
Overnight Temperatures in the Central (US) Rockies
It is evident that the recorded temperature of the freezer is fairly typical in temperature when compared with the weather statistics on the highest Colorado mountains.
The bottles were all removed from freezer at 7:22 AM on October 12 2007. This is 11 hours 15 minutes after their placement. As per my experience 10-14 hours is a typical time to climb in a day for winter ascents.
Nalgene bottle with OR insulating jacket
Notice that the Nalgene bottle (which was placed upside down in the freezer is frozen. It still did better than expected. Approximately 40% of the water in the bottle was frozen. The remaining portion of unfrozen water was at about 32F. Since I’ve had water freeze completely solid on climbs, it shows how cold those days were on those particular climbs.
This did surprisingly well. I have actually had water turn slushy in it on very cold days, but for this test the water stayed well above freezing. The measured temperature at the end of the test was 42.4F, well above the freezing threshold.
This is the best performer. I have never had water freeze while using this product. For this test the measured temperature at the end of the test was 50.2F, well above freezing.
For cold winter climbs, do not rely solely on Nalgene bottles and insulating jackets unless you have them close to your body the entire time. At a minimum, take at least one high quality thermos (such as the REI one) to make sure you have water available after the Nalgene bottle freezes.