Unlike other organs, the testicles are located outside the body because sperm production
is adversely affected by higher temperatures. So, yes a fever can have a negative effect on sperm count. The higher the fever the greater the chance for a temporary reduction in sperm
count.
it may lead to the other person to get fever or it may cause infection. it depends upon the nature of the body. If he is a married person he must be very careful in having intercourse with his spouse.