A Haitian man who died in Immigration and Customs Enforcement custody this spring succumbed to complications from a tooth infection and dental disease, according to the Maricopa County Medical Examiner's Office.

Separately, six people were found dead inside a railway car in Laredo, Texas, with preliminary results from the Webb County medical examiner indicating that at least one person died from hyperthermia. The remaining five deaths are likely attributed to the same cause, officials said.

The Laredo incident highlights growing concerns about the dangers facing migrants during summer months along the U.S.-Mexico border. Immigration advocates have warned that the coming months represent the most perilous time of year for people making the journey across the southern border.

Hyperthermia occurs when the body becomes overwhelmed by extreme heat and can no longer regulate its temperature. The condition can be fatal, particularly in enclosed spaces like railway cars where temperatures can reach dangerous levels.

The deaths come as border crossings continue and temperatures are expected to rise throughout the summer months. Both incidents underscore different health and safety risks faced by migrants in federal custody and during border crossings.