It wasn't the first time he'd gotten burned. It wouldn't be the last either. Each encounter, each fight took a toll on the Fire Lord.
Thank Spirits he had her, though. Each time he returned home, he was welcomed with a kiss and a scornful remark about how he deserved to get his "ass kicked" to knock him down off of his pedestal.
She'd sit him down, tie his hair up in a loose, messy, and sure-as-Agni painful bun atop his head and find her canteen, stringing out the water and pressing it against whatever wound he'd gotten that day. It would sting at first, and after the fifth time she stopped warning him. He got used to it, but still cringed a little when the icy cold hit his skin.
When she'd wrapped it and forgiven him with a kiss, it immediately felt relieved. Knowing that was in his healer's, his wife's, his lover's, his soul mate's hands, he couldn't have felt more soothed.