Tarn tries to hide his fear upon hearing those words. The only trace of it hides in his eyes as they flit nervously to Zarya's as if looking for any sign of dishonesty. He finds nothing.

Can he really lose his limbs from the cold? Will the burning pain in his fingers really persist?

"Then the damage is already done. Your jacket won't help that."

Tarn's frozen legs can't keep up with Zarya's pace as they keep walking. He remains several feet behind her despite efforts to walk faster. The promise of warmth is honestly the only thing keeping him going.