Do insulated water bottles keep water cold in 90+ degree heat?

Good double wall vacuum insulated bottles keep water cold for 12 24 hours, even in extreme heat. In 90+ degree weather, expect ice to last 8 12 hours in a quality bottle. The key is the vacuum seal between the inner and outer walls it eliminates heat transfer. Brands like Hydro Flask, YETI, and Stanley perform best. Single wall bottles or plastic bottles will warm up within 1 2 hours in direct sun.