Compliance of warming blankets regarding surface temperature

Hi everyone,

I see that almost all manufacturers of warming blankets are compliant with IEC 60601-1. So I assume they are also compliant with requirements for surface temperature of applied parts, which is maximum of 43 °C for applied part having contact with the patient for longer than 10 minutes. But how it is possible then that operational temperature of a warming blanket can be 43°C +/- 1.5°C (see image below)? I´m sure i understand something wrong, but I don´t know what exactly.

 

I´m not sure. If so, how big the uncertainty can be: +/- 1, +/-3, +/-5°C? For our medical products we ensure during design validation that the surface temperature can never exceed 43 °C in order to be compliant with IEC 60601-1. And the measurement uncertainty is already taken into account, i.e. if my temperature probe has uncertainty of +/-1°C, we allow maximum measured value of 42 °C, otherwise it will be fail.
Additionally we have thermal cutoff at 43 °C in case of some failure. But theese guys with warming blankets can heat the whole patient body at around 43 °C and the thermal cutoff is just at 47°C +/-2°C. I really don´t understand it.