The most predictable thing about New Mexico springs is unpredictable temperatures, as evidenced in recent days. It’s not unusual for us to have temperature swings of fifty degrees or more in a 24-hour period this time of year. Late and sudden frosts can damage or destroy those carefully planted little seedlings in a matter of hours. Don’t panic. There are measures that can be taken to protect them.
http://www.growgardentomatoes.com/frost-protection.html offers a great list of options to keep your plants warm and healthy. So keep an eye on the forecast, stay prepared, and your garden will survive without harm.