**Yes—telling his teacher and asking her to get help if she notices symptoms is entirely appropriate.** You’re sharing information she needs to care for him at school. The reasonable boundary is asking her to notice and respond during normal supervision; continuous monitoring or medical assessment needs a separate arrangement with the school.

It’s reasonable to:

- Explain that colds can trigger his asthma, even though he usually has no symptoms.
- Describe his specific warning signs, especially ones he may not report himself.
- Ask her to contact the nurse or designated staff member promptly if he has breathing difficulties, worsening coughing, or seems unusually unwell.
- Ask that he be allowed to report symptoms and get help immediately.

For ongoing care, involve the school nurse—or whoever handles health needs if there isn’t one. Provide a **written asthma action plan from his clinician**, arrange access to prescribed rescue medication under school procedures, and confirm who responds when the nurse is unavailable. NIH guidance specifically recommends sharing the action plan with school staff. [NIH: Asthma in Children](https://www.nhlbi.nih.gov/health/asthma/children)

A short email could say:

> Hi [Teacher],
>
> [Child] has asthma that is usually quiet but can flare up significantly when he has a cold. He has a cold and cough today, although he seemed well enough for school this morning.
>
> If you notice increased coughing, difficulty breathing, or that he seems unusually tired or unwell—or if he tells you his breathing feels difficult—please contact the nurse/designated staff member promptly. We’re available at [numbers] if he needs to come home.
>
> I’m also contacting the nurse to confirm his asthma plan and medication arrangements. Please let me know if there’s a school procedure we should follow. Thank you for helping us keep him safe.

For obvious breathing distress, the arrangement should be to **bring help to him and keep an adult with him**, rather than send him to the office alone. Severe symptoms require the school’s emergency response, without waiting for a parent to arrive. [NIH: Managing Asthma—A Guide for Schools](https://www.nhlbi.nih.gov/files/docs/resources/lung/NACI_ManagingAsthma-508%20FINAL.pdf)

Finally, whether he is well enough to attend is a separate decision from what the teacher can reasonably do. If he needs frequent breathing checks to remain safe, speak with his clinician and the school nurse before relying on classroom supervision.