The main hazards in the Sangre de Cristos are altitude and weather. Altitude sickness is common among visitors from sea level who have not taken the time for some acclimatization in the valley. Two or three days spent in Santa Fe or Taos or even the lower Albuquerque before heading into the mountains will reduce your chances of troublesome or even serious illness. The primary weather-related issues are hypothermia and lightning. Freezing rain or snow can fall on the summits at any time of year; backpackers in the high country should have down or synthetic sleeping bags good for temperatures of 20 F -7 C in the summer. Good rainwear is a must, particularly in July and August. Thunderstorms at these times make the high summits decidedly unhealthy places to be after about 1 p.m., and can form considerably earlier in the day.
Some care should be taken when visiting the small towns around the mountains. Several of the villages on the west side e.g. Chimayo, Cundiyo, Truchas lie along a major "pipeline" for narcotics coming into the United States from Mexico, and the villagers do not take kindly to outsiders poking around in places where they don't belong. There have also been ethnic tensions between the predominantly Hispanic residents of these towns and Anglo visitors. These often are manifested in trouble in bars, for which reason there is no "Drink" entry in this article; small-town bars are simply best avoided in this region. Vandalism of cars at campgrounds and trailheads has also been a problem. It's wise not to drive an ostentatious vehicle to these locations if you'll be leaving it unattended overnight; vandalism seems to increase in direct proportion to the value of the vehicle being vandalized.
One final note: northern New Mexico has an unfortunate and well-deserved reputation for problems with drunk drivers, and it's a definite problem in this area. Drive suspiciously, and if you must park along a roadside at night, get as far off the road as possible, as fatal encounters between intoxicated drivers and pedestrians are all too common.
talk
English really is the usual language in this area, despite rumors to the contrary. However, it's not necessarily an inhabitant's first language. Many residents speak Spanish not just at home but in public, in a dialect that has significant ties to seventeenth-century Spain as well as a number of distinctive regional quirks. The Spanish-speaking visitor may find it interesting to listen and learn, but no knowledge of Spanish is required to get around.