What is the status of a kli whose primary use would be forbidden on Shabbos, but it is only used in a case of Pikuach Nefesh. Is it a Kli Shemelachto LeIssur or Kli Shemelachto Leheter?
- Defibrillator - it uses electricity (so it should be a kli shemelachto leissur), but the only time it's used is when someone is in a state of pikuach nefesh (so it should be a hetter). I heard that there is a machlokes if a kli shemelachto leheter can become muktza machmas chisaron kis.
- Gas Mask (possibly) - it could be a kli shemelachto leisssur (it could be borer, similar to a water filter). On the other hand the only time it's used is when there is a sakanas nefashos.