>>1647368>Can pour boiling water directly inHere are some general rules for plastic and synthetic water bottles:
The best before date on a store bought water bottle is not when the water goes bad. It's a date for when the bottle starts to break down and seep chemicals into your water. Chemicals in water bottles didn't disappear with BPA.
Heat will speed up the process of chemical leakage in to your water. NEVER put hot or boiling water in your plastic/synthetic bottle.
The same plastic is used to line canned food. DON'T heat your canned food in the can/tin it came in.
Aluminum bottles are also lined with plastic. The plastic will degrade, break down and poison you with chemicals. If you drop and damage your aluminum bottle, the plastic lining inside will crack and start to fall off. The inevitable contact between your water and the aluminum itself is even more cancerous. Avoid at all cost. (Yes cheapo aluminium pots and pans will harm you as well)
If you need to boil water on your hike, use stainless food-grade bottles.
Don't try to save on using the same synthetic bottle for years. What you save in dollars you lose in health.
If you need to bring water with you, store bought plastic bottles are the lightest alternative. You can of course add boiled water to these, but let the water cool all the way down first. Remember to throw the bottles out when you get home.