Speedo, if he’s on night shift, he might be grumpy on a morning phone call to you due to no sleep. If he’s on day shift he might be grumpy due to knowing he’s facing a grueling day or, worse yet, another hurry-up-and-wait day.
Firefighting is really stressful. My sister, a former hotshot, had ups and downs too. Goes with the territory. I just tried to be understanding and positive. With a love interest it might be harder. In new relationships you fall into each other and want to fall in head over feet. I’d just say don’t loose yourself when you do. Keeping your feet on the ground may be the best gift you can give him.