An interesting article about temperature measurement. They key is to use infrared for process control e.g. industrial work flows. But because infrared is fast and small it can be used for wearable applications too. And what sounds fun is that you can implement networks to measure temperature within groups and install close loop control...

Some features:
IR thermometers allow the quick, safe measurement of temperature, especially of objects that are moving, extremely hot or difficult to reach.

When pointed at the target, the IR thermometer captures the infrared energy that is naturally emitted from all objects, directs it through its optical or lens system and converts it into an electrical signal.

These models vary in capability from basic single-point temperature sensors to networked sensors supported by digital communications.

When the requirement is for networked, multi-point monitoring, 'smart'IR sensors with built-in digital communications provide a solution.

The Manufacturer: Raytek Worldwide, Santa Cruz. USA