Can I use very hot water in a Watercell (hot water bottle/showering/cleaning)? Can I freeze a Watercell?

There are no issues with the construction of the Watercell for hot water use – the TPU film and RF-welded seams can tolerate water temperatures above boiling and even freezing. However, there are important safety and usage considerations to keep in mind.

Using as a hot water bottle

We do not recommend filling a Watercell with boiling or near-boiling water for use inside a sleeping bag.

• The cap and threaded fill port are made from different materials and may expand at different rates when exposed to very hot water.
• This could cause water to seep out – and if the Watercell is inside a sleeping bag, there’s a risk of scalding injury.

Using as a shower

• Safe for hot water up to 60°C / 140°F – well above normal showering needs.
•  If you will be adding hot water, we would always suggest partially filling the Watercell with cold water first.

Cleaning with hot water

• Hot water can be used to wash out a Watercell, but keep it at or below 60°C / 140°F

 (still well above that needed for dishwashing).

• For detailed cleaning instructions, see our FAQ: How do I clean my Watercell / Pack Tap?

Freezing a Watercell for cooler use

• You could freeze water in a Watercell X safely, as long as you leave plenty of room for expansion.
• The welds, laminates, and cap are not harmed by temperatures cold enough to freeze water.
• As a consideration, there are simpler and less-expensive water containers that may be more practical.