confident, the NCDC is run by the US government, whilst you may be sceptical about them, surely the data collected by them can be relied on. Why won't you accept their data, any real reason?
Just on your matter of the temperature of the human body, without being pedantic, individuals can have a "normal" temperatures a degree over or under that figure you quoted. Just extending that line of thought, has anybody taken into account the effect the actual human body is having on the temperatures. Each body is a mini boiler generating and dispersing heat into the atmosphere on a continous basis. The more people on the planet, compounded by the growing problem of obesity must have some effect, has anyone seen any data on this.