Obviously this exact code won't work. I don't know how to freeze a player, but I'm pretty sure that's how you would make sure that the timeleft was 15 seconds. Not sure if the (timeleft="0.375" ) is the right time :/
Code:
for(new i;i>0;i++)
{
new timeleft=Float: get_timeleft()
if(timeleft=.0375)
{
//whatever the code is to freeze a player, I'm not sure :/
}