In Muay Thai sparring, most of the times when I go to throw a body punch it is because I see the defences of the head being too tight for a throw towards the head. The result of those attempts is commonly me bending down to reach the abdomen, and getting a direct hit in the face from a jab or even a cross. I have seen this happen to other people as well, especially novices with less than a year or two of experience.
My question is; when are you in a good position to throw a punch to the body/abdomen and when are you not in a good position. Accounting of course for the situation/position your opponent is in. Eg. After you have just thrown a jab? After you have made a quick side step and you are not in the direct line of a counter punch? After a failed combo of the opponent?