1. Slow down: Recovering from winter illness means you need to work up to your usual exercise routine, and don't overdo it after a bad-weather break. Don't push through pain or increase your workouts rapidly.
2. Dress warm: Keep muscles warm in breathable layers and remember to wrap up warm after your exercise to avoid chills and for optimal recovery.
3. Think cyclically: Have a year-round plan for your fitness and use the winter months to try new things and focus on different techniques - you can't go hard out all year. Ask your physiotherapist for a full "muscle balance assessment".
4. Stretch: You might be able to get away with not warming up in summer, but you're running the risk of serious injury if you don't fully warm up in colder weather.
5. Rehydrate: Just because it's cold it doesn't mean you're not sweating. Keep up your fluid intake.