You should always ensure that you have adequate travel and health insurance to cover the countries you are going to, for the period of time you will be there. Please also check it covers you for business purposes.
You should also make sure you have a valid European Health Insurance Card which will cover you for emergency healthcare in Europe. It entitles you to the same level of treatment of a resident of that country.
United Kingdom
Republic of Ireland
Polska
România
Republica Moldova
Российская Федерация
Украина
Республика Беларусь
Литва
Латвия
Эстония
Deutschland
Schweiz
Österreich
Lichtenstein
Belgien
Luxemburg
Magyarország
Česká republika
Slovenská republika.
España
Italia
Bulgaria