Stay safe & healthy
Historically, Uruguay has enjoyed a very low rate of violent crime compared to its neighbors. Thus, Argentines and Brazilians traditionally go on vacation in Uruguay because they love not having to worry about being carjacked, kidnapped, or murdered while on vacation. Even today, Uruguay is still relatively free of those types of crimes.
However, this does not mean that Uruguay is crime free. The major differences are that most Uruguayan crimes are either nonconfrontational or do not involve the gratuitous use of firearms. Montevideo in particular has seen its crime rate gradually rise since the severe 2001-2002 financial crisis, and now has moderately high levels of theft, burglary, and robbery similar to those found in major U.S. cities. Fortunately, Punta del Este and most rural areas continue to enjoy relatively low crime levels. As long as you take basic precautions in Montevideo (i.e., use a money belt and/or hotel safe for valuables, look alert, and keep out of obvious slums), you will have a very safe trip.
Cannabis is one of the most widely used drugs in the country and legal as well. Uruguay is the first country in the world where the sale, growth and distribution of cannabis is legal. Regarding the legality of marijuana, possession for personal use is not penalized if it concerns minor quantities (a few grams), either Uruguayan or foreign. Possession of major quantities (for example, one kilogram) is illegal and punishable by law. Remember that the recent legalization of this drug as for the personal use (medicinal or recreational), sale or storage of the plant (~480 grams per year) is only for Uruguayan citizens of 18 years and above (natural or legal citizenship) with legal capacity. Likewise with alcohol, driving under the influence of marijuana is not allowed, and such breach may carry a fine.
In an emergency, call 911 or 999. For firefighters, call, 104.
Tap water is safe to drink in all major cities. The Hospital Britanico (British Hospital), SUMMUM and BlueCross & BlueShield Uruguay have a European-quality service and they are clean and efficient. Asociación Española, Medica Uruguaya and CASMU are the largest healthcare companies in Uruguay and they have a European-quality level. Just don't make any unwise drinking decisions.
Tropical diseases present in Uruguay include chagas disease. Its prevalence is low and endemic only in the north of the country. Mostly, the only way of transmission is vertical (from mother to child). No vaccine exists against either of these, so you need to watch out for mosquitoes. In practice you won't encounter insects in Uruguay very frequently, at least during the Southern Hemisphere winter.