Waterproof?
Can I wear my Apple 4 watch in the shower?
Apple Watch, watchOS 4
Can I wear my Apple 4 watch in the shower?
Apple Watch, watchOS 4
Hot water and soap are both not recommended. See About Apple Watch water resistance - Apple Support
Some people do. (I never do) The watch is water resistant, not waterproof.
First, it's NOT waterproof, it's "water-resistant." Apple says that you can wear it in the shower but be sure to rinse off any soap when you're finished. Personally, I wouldn't do it. Water damage is not covered by the warranty.
Hot water and soap are both not recommended. See About Apple Watch water resistance - Apple Support
Your link says nothing about hot water.
Be that as it may, I wouldn't shower with it anyway.
Waterproof?