Summer Heat: Why You Should Never Leave Tefillin in Your Car

Summer heat can do more than damage electronics or groceries left in a parked car. According to rabbinic officials, it can also permanently damage tefillin, potentially rendering them invalid for use and requiring costly repairs—or even replacement.

Extreme Heat Can Damage Tefillin

Rabbi Ovadia Dahan, chairman of the Ashdod Religious Council in Israel, has issued an urgent warning to drivers and travelers not to leave tallit and tefillin bags inside vehicles parked in the sun.

Tests have shown that the temperature inside a closed car can quickly climb above 158°F (70°C) on hot summer days. Under these conditions, the ink on the parchment inside the tefillin can dry out, soften, or cause the letters to stick together. When this happens, the tefillin may become halachically invalid and suffer irreversible damage that can cost thousands of dollars to repair or replace.

Several Cases Reported

According to the Ashdod Religious Council, several pairs of tefillin were brought in over the past month after being damaged by extreme heat. In each case, the letters on the parchment had fused together after the tefillin had been left inside a hot vehicle, whether in the trunk or on a car seat.

To help prevent unnecessary financial loss and disappointment, Rabbi Dahan strongly advises travelers never to leave tefillin inside a parked car, even for a short time. Instead, they should carry them with them or store them in a cool, shaded, air-conditioned place.

His warning serves as an important reminder that during the summer months, protecting sacred items from extreme heat is just as important as safeguarding them from theft or physical damage.