Damage and heat.
Your Night Wolf has 5 damage, you are doing five attack rolls (using mulitple attack rolls) and each does 1 damage. Adding special abilities (like HT) to the attack roll doesn't change that you assigned 1 damage of your 5 to that attack roll. It's still going to do the damage. If all five hit, the Night Wolf would deliver 5 damage + 1 heat.
If you had a unit with 1/1/1 and HT2/2/2, then you would need two attack rolls. The first would have the 1 damage and 1 heat, and the second would only have the 1 heat. This is the only time you'd have an attack roll that didn't do damage, where your HT special is greater than the damage and you have to have a separate HT attack roll(s).