Is hardwood flooring safe from termites?
If you have a traditional wood framed house, termites in the flooring would be the least of your problems. Structural issues due to termites in load bearing walls would be much worse. 

Are you on a slab or crawlspace? If you're on a crawlspace, you already have a wooden subfloor anyway.

Do you have a current termite problem, or are they common in your area? If so, you'll want to have a pest control company come out and do an inspection. Get a quote for remediation if they find any, and ask them if they offer termite bonds. This is essentially insurance against termite infestation in the future. The pest control company will usually come out once or twice a year (for a fee) and either spray termiticide or put out poison bait traps. If they find termite damage while you're paying for the maintenance, they'll cover the cost of remediation.