Our body and health should not be taken for granted nor neglected since we only have one, therefore taking care of your body is important for living a happy life. Dehydration is a foreign concept to me since I always have a bottle of water around me and I dress appropriately to the weather. From the modules prevention tip, it was stated there to eat watery fruits and vegetables, I mostly eat sliced cucumbers, which as you know contains 96% of water, ergo I'm pretty hydrated. Most of the given prevention tips is something I'm already doing so thats good.
Overexertion was very frequent for me before when I was still attending karate class, I never did suffer any injuries from it since I made sure that I warmed up and cooled down (stretching) before and after the practice. The tips from the module was very good since its something my karate teacher will have us do or pay attention to. Hypothermia is something that I have never experienced yet since it doesn't really get too cold in our country to the point that you'll freeze, hyperthermia on the other hand, this we frequently experience every summer.
What I do to avoid it is to stay indoors or under shades and if going outdoors is unavoidable I always wear a hat and use an umbrella. I make sure to stay hydrated and have a water bottle near me to cool down and dress lightly. This are my personal practices when it comes to dehydration, overexertion and etc, comparing it from the tips from the module I'd say they are pretty similar.