My 6 month old male kitten, Pepper, has just started into heat and has gone missing. It is very cold here in the country. With lots of hiding places, I wondered how I may go about finding him and if there is a possibility that he will find his own way home?

A male going into heat?? The females go into heat but, the your male cat might have "found a female in heat" .

Tuna fish. Put it outside, he'll smell it a mile away. Of course other animals will also be attracted to the free food.

Any sign of him yet?

If he's not neutered, the chances of him returning are nil-he'll go with his hormones, ALWAYS. That's why spaying and neutering are so important at 6 months of age. Unfortunately, these guys' luck isn't so great out on their own because with the hormones kicking, they are not paying attention to the dangers that surround them-predators, cars, etc. If he does come back, nip things in the bud quickly-if you catch my drift!