Winter Field Day is an emergency communications exercise that takes place yearly on the last weekend in January. The concept is similar to the ARRL Field Day held at the end of June.
If you are really ambitious and hardy, you can set up and operate outdoors. In the north country, this will probably mean operating under pretty adverse conditions. In the southern states, conditions may be more pleasant than in June.
You can also just operate from your normal location. Yo u might use battery or generator power,or a temporary antenna to simulate emergency conditions.
The middle ground is to operate "deployed" but in a comfortable shelter, or at an EOC or other established emergency communications facility.
Whatever you do, participating in Wiemergenciesnter Field Day can be fun and is good practice.
Details at https://winterfieldday.org/