It was midsummer, less than three months before Canada legalized recreational marijuana, and Vic Neufeld had a problem.

The chief executive officer of Aphria Inc. had just hired 50 people to work in the pot producer¡¯s greenhouse in Leamington, Ontario, and by the end of the first week all but eight had quit.

¡°Those are really hot, humid months and working in a greenhouse, as much cooling and airflow as we can provide, is still pretty darn hot in July and August,¡± Neufeld said in a phone interview.