Are we allowed to use a thermometer on Shabbos to check if we have high fever?
In my case, I went to the doctor on Thursday and I got antibiotics. I had 103.5 fever and the doctor said if I feel sick on Shabbos I should call even on Shabbos due to COVID-19. I said if I feel sick, I’ll take a Tylenol so I don’t have to call on Shabbos.
You should use a non-electric thermometer if possible.
If the doctor says to call if the fever is high you should call and not rely on taking a Tylenol. If possible, call with a shinuy.
See here regarding the thermometer on Shabbos: