taking temp orally - surgipack thermometer

Jacinta
When taking your temperature 🤒 
How do you guys do it?
Would you get best results to just stick it in and turn it on straight away. 
Or put it in. Give it a couple of minutes and then turn it on. 
I use the "Surgipack ovulation digital thermometer(6332)"
Or should i just follow the instructions 😂 and have it in my mouth 4mins prior then turn it on. 
Thanks