It's pretty unlikely you'll be wandering Paris in shorts - especially since you're used to such warm weather -- the oldtimers count mid-May as the final frost date! (sometimes it works that way, sometimes it doesn't -- but they publish garden advice to protect your plants until mid-May).
Dihydrogen Monoxide (DHMO) is a colorless and odorless chemical compound, also referred to by some as Dihydrogen Oxide, Hydrogen Hydroxide, Hydronium Hydroxide, or simply Hydric acid.
Prolonged, unprotected exposure to solid DHMO, or inhaling it can be fatal. Despite these dangers, DHMO is used ubiquitously by industries, and is readily available to the public. Join the fight, and help get this troublesome, and potentially lethal chemical banned.