Sure it is a good idea to treat hypothermia at the first signs. But, and I always seem to come up with buts, in most cases you can't really recognise the symptoms by your self. Most people don't notice it at first. They just feel cold. As we all would. Then as it advances the mind is affected. Then things go downhill fast. Sure if anyone gets dunked in the river at 20 below they are going to realize that they need to get warm now. The reason most people that die from it in those mid temperatures is that it creeps up on you slowly then affects your judgement about what is happening. The person that will spot the suigns is your partner not you.

The case wheer after drop was first recognized was a group of fishermen haulled out of the ocean. They were treated for hypothermia. After the initial warming they all appeared to be recovering then suddenly died of heart failure. This is what started researcher to question what happened and the answers were what has formed the current recommandations for treatment.