I think the key would be maintaining the body heat with what every you have, be it a survival blanket, sleeping bag, tarp what ever. This means constant monitoring to check and recheck till the evacuation was completed. This is especially so if your patient/casualty is borderline hypothermic or already hypothermic. This would call for the best insulation available to you plus additional heat sources e.g warm saline, heat packs, fire etc.......

To answer your question, we will only know if it is too much or too little when we check on the temperature on a regular basis.Of course in some cases, too much is better than too little.

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