1 Corinthians 3:16-17
16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?
17 If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are.
Does the above mention of a believer being "destroyed" mean that they will be sent to Hell?
The context of the passage in question is dealing with the fact that the Corinthians are "carnal" (1 Corinthians 3:1-4), which is to say, living after the flesh.
This carnality included fornication (1 Corinthians 5:1, 6:15-16), which is a sin against one's own body, which is the "temple of God", as is seen again in the following passage:
1 Corinthians 6:12-13, 6:18-20
12 All things are lawful unto me, but all things are not expedient: all things are lawful for me, but I will not be brought under the power of any.
13 Meats for the belly, and the belly for meats: but God shall destroy both it and them. Now the body is not for fornication, but for the Lord; and the Lord for the body.
18 Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.
19 What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own?
20 For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's.
The above sheds light on our passage in question, because it shows clearly that "temple of God" is the flesh that we temporarily have here on earth. If we "defile the temple of God", as the passage in question says, through sins like fornication, God will turn over our bodies to be destroyed:
1 Corinthians 5:5
5 To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
The above verse is just two chapters after our passage in question, and shows clearly that its mention of "him shall God destroy" (1 Corinthians 3:17) refers to the destruction of the defiled "temple", the flesh.
This passage is a warning to avoid fornication, primarily, and it teaches that God will chasten a believer if they don't (Hebrews 12:6). It has absolutely nothing to do with a believer "losing their Salvation".