I have a body temperature of 35.5 degrees Celsius. Is that normal?

Hmmm ... it is, at first glance, a bit below average .... but as the normal temperature is the CORE temperature, it is all too easy to take an incorrect temperature measurement.

There is a good reason why people use those thermometers you put ... cough .... where the sun don't shine. They provide an accurate reading in a suitable (albeit somewhat uncomfortable) location.

BONUS QUESTION; do you know the difference between an oral and a rectal thermometer?

... the taste ...

It suggests you are getting a little colder than you should be. Hypothermia is considered to be anything under 35 degrees C.