[Well, that kind of answer wouldn't be a complete surprise. It's the kind of answer he gets fairly often from some of the other heroes. But he's already pretty stressed by the time limit and the implication that his new friend's injuries are pretty severe, so Tony isn't feeling that up for humor.]

You sound like all kinds of fun. I'll be really disappointed if you don't deliver.

[His joke is overridden when the next text warns him to be careful, and by Tony's huffing breaths it is clear when he reads that.]

It's fine. I'm fine. I'm not the one that's hurt here. I've had worse than just some snow.

[Which is why he's protesting like a twelve year old.]