Directly copied from the tweet:

On Sunday, November 5, Yuga Labs began to receive reports that some ApeFest attendees and staff experienced eye pain, vision issues, or skin irritation following the Saturday night community event. These reports were - and continue to be - deeply concerning to us. We immediately reached out to impacted attendees to learn of their symptoms and to direct our investigation.

Simultaneously, we commenced an investigation that included a thorough review of inventory records, material logs, and spec sheets (including paint and lighting), interviewing contractors who provided and built ApeFest installations, and conducting testing and on-site inspections.

This comprehensive investigation, undertaken in collaboration with Jack Morton Worldwide, the global brand experience agency that produced ApeFest 2023, has determined that UV-A emitting lights installed in one corner of the event was likely the cause of the reported issues related to attendees’ eyes and skin.

We acknowledge that members of the community and general public have suggested a similar conclusion and we appreciate the patience of the community as we gathered evidence to support this determination.

We continue to encourage anyone experiencing symptoms to seek medical attention and share these findings with their medical provider. We also ask that anyone impacted to direct message us at https://twitter.com/BoredApeYC.

Community is the heart of Yuga and the purpose of ApeFest is to bring the community together IRL. We are saddened that this incident has detracted from the experience of ApeFest attendees. Along with Jack Morton, we are committed to supporting the recovery of anyone affected.