What is a good temp. to kill germs in a small office space of about 35 people?

212 degrees fahrenheit or 100 degrees celsius should do it.

about 20 degrees

Its not the temp that matters, its the air flow. U need to set a pot of boiling water in the corner of the room with a tablespoon of clorox in it . The clorox will kill airborne germs in the air.
Or keep hot steam salt water flow in the air.
Moisture is the key. Lysol all doorknobs, phones, daily.

You mean air temp? Keep it around 70, but you need an air purifier ( and a humidifier when the air is dry ) and people need to use hand sanitizer. Also, did you know that your keyboards, desks, and telephone have more germs than a bathroom. Clean them every day!!!!

Most germs die at a temp of about 45 degrees. But hospitals operating rooms are at a constant 66 I believe. But that is for the doctors comfort they still treat for infections.

Forget it, my friend! You can run around swabbing down phones and keyboards and doorknobs, but germs are everywhere, including airborne. Your kids are bringing them home from school. It's no use obsessing over it. Germs are a part of life.

The point is, germs attack us and we get sick only when our immune systems are suppressed. Stress relief, adequate sleep, healthy eating and 1000 mg. of Vitamin C every day will support your immune system so you do not fall prey to every virus and bacterium that comes down the pike.

Now, a separate concern is what's called "sick building syndrome." Some office buildings were built with sealed windows and closed ventilation systems. Chemicals from carpeting, upholstery etc. pervade the air and lead to headaches and allergy symptoms, making some people seriously ill. That's a whole different issue and needs to be taken up with building management!