Are Stomach Ache, Sore Throat With Low Temperature In A Child A Cause For Concern?

My son has complained of a stomache ache and sore throat this morning, I took his temperature and it was 35 degreees which seemed a bit low, He looks okay in himself apart from the above. I have sent him to school and told him to inform his teacher straight away if he does not feel right or anything changes. Was I right to have sent him to school or should I have took him to the doctors with the low temperature?